diff --git a/lib/metadata/fieldsetregistry.inc.php b/lib/metadata/fieldsetregistry.inc.php
index 7baeab1..4475318 100644
--- a/lib/metadata/fieldsetregistry.inc.php
+++ b/lib/metadata/fieldsetregistry.inc.php
@@ -97,12 +97,53 @@ class KTFieldsetRegistry {
 
         // FIXME delegate.
         $oFieldset =& $fieldsetOrType;
-        if ($oFieldset->getIsConditional()) {
-            return PEAR::raiseError(_kt("Conditional Fieldsets are not yet implemented"));
-        } else {
+
             $widgets = array();
             $fields = $oFieldset->getFields();
 
+	if ($oFieldset->getIsConditional()) {
+	    $iMasterId = $oFieldset->getMasterFieldId();
+
+	    $oMasterField = DocumentField::get($iMasterId);
+	    
+	    $newfields = array();
+	    $newfields[] = $oMasterField;
+	    foreach($fields as $oField) {
+		if($oField->getId() != $iMasterId) {
+		    $newfields[] = $oField;
+		}
+	    }
+	    
+            foreach ($newfields as $oField) {
+                $fname = 'metadata_' . $oField->getId(); 
+                $value = null;
+                
+                if (!is_null($oDocument)) {
+                    $oFL = DocumentFieldLink::getByDocumentAndField($oDocument, $oField);
+                    if (!is_null($oFL) && (!PEAR::isError($oFL))) {
+                        $value = $oFL->getValue();
+                    }
+                }
+                
+		$widgets[] = $this->oWF->get('ktcore.widgets.conditionalselection', 
+					     array(
+						   'label' => $oField->getName(),
+						   'required' => $oField->getIsMandatory(),
+						   'name' => $fname,
+						   'value' => $value,
+						   'description' => $oField->getDescription(),
+						   'vocab' => MetaData::getEnabledByDocumentField($oField),
+						   'id_method' => 'getName',
+						   'label_method' => 'getName',
+						   'unselected_label' => _kt("No selection."),
+						   'simple_select' => false,
+						   'master' => ($oField->getId() == $iMasterId),
+						   'masterid' => $iMasterId,
+						   'fieldset' => $oFieldset->getId(),
+						   'field' => $oField->getId(),
+						   ));
+            }
+        } else {
             foreach ($fields as $oField) {
 
                 $fname = 'metadata_' . $oField->getId();
@@ -165,13 +206,17 @@ class KTFieldsetRegistry {
                 }
             }
 
-            return array($this->oWF->get('ktcore.widgets.fieldset',array(
+
+        }
+	
+	return array($this->oWF->get('ktcore.widgets.fieldset',
+				     array(
                 'label' => $oFieldset->getName(),
                 'description' => $oFieldset->getDescription(),
                 'name' => $sContainerName,
                 'widgets' => $widgets,
             )));
-        }
+	
     }
 
 
@@ -184,7 +229,26 @@ class KTFieldsetRegistry {
         // FIXME delegate.
         $oFieldset =& $fieldsetOrType;
         if ($oFieldset->getIsConditional()) {
-            return PEAR::raiseError(_kt("Conditional Fieldsets are not yet implemented"));
+            $validators = array();
+            $fields = $oFieldset->getFields();
+            
+            if ($bIncludeAuto) {
+                $widgets = $this->widgetsForFieldset($oFieldset, $sContainerName, $sDocument);
+                $validators = kt_array_merge($validators, $widgets[0]->getValidators());
+            }
+                    
+            foreach ($fields as $oField) {
+                $fname = 'metadata_' . $oField->getId();
+
+		// Change back to 'membership'
+		$validators[] = $this->oVF->get('ktcore.validators.membership',
+						array(
+						      'test' => $fname,
+						      'output' => $fname,
+						      'vocab' => MetaData::getEnabledValuesByDocumentField($oField),
+						      'id_method' => 'getName',
+						      ));
+	    }
         } else {
             $validators = array();
             $fields = $oFieldset->getFields();
@@ -243,13 +307,14 @@ class KTFieldsetRegistry {
                 }
             }
 
-            return array($this->oVF->get('ktcore.validators.fieldset',array(
+        }
+	return array($this->oVF->get('ktcore.validators.fieldset',
+				     array(
                 'test' => $sContainerName,
                 'output' => $sContainerName,
                 'validators' => $validators,
             )));
         }
     }
-}
 
 ?>
diff --git a/plugins/ktcore/KTCorePlugin.php b/plugins/ktcore/KTCorePlugin.php
index 3e4b597..5e59514 100644
--- a/plugins/ktcore/KTCorePlugin.php
+++ b/plugins/ktcore/KTCorePlugin.php
@@ -181,6 +181,8 @@ class KTCorePlugin extends KTPlugin {
         $this->registerWidget('KTDescriptorSelectionWidget', 'ktcore.widgets.descriptorselection', 'KTWidgets.php');
         $this->registerWidget('KTCoreFolderCollectionWidget', 'ktcore.widgets.foldercollection', 'KTWidgets.php');
 
+        $this->registerWidget('KTCoreConditionalSelectionWidget', 'ktcore.widgets.conditionalselection', 'KTWidgets.php');
+                
         $this->registerPage('collection', 'KTCoreCollectionPage', 'KTWidgets.php');
         $this->registerPage('notifications', 'KTNotificationOverflowPage', 'KTMiscPages.php');
 
diff --git a/plugins/ktcore/KTWidgets.php b/plugins/ktcore/KTWidgets.php
index ce22ff3..3226c47 100644
--- a/plugins/ktcore/KTWidgets.php
+++ b/plugins/ktcore/KTWidgets.php
@@ -767,4 +767,160 @@ class KTCoreCollectionPage extends KTStandardDispatcher {
 }
 
 
-?>
+
+// based on the selection widget, this carries a mapping array,
+// which is converted to JSON and inserted into the output. javascript
+// enforces the various relationships between conditional fields.
+
+class KTCoreConditionalSelectionWidget extends KTCoreSelectionWidget {
+    var $sNamespace = 'ktcore.widgets.conditionalselection';
+
+    var $sIdMethod;
+    var $sLabelMethod;
+
+    var $bIsMaster;
+    var $bMappings;
+    
+    function _getFieldIdForMetadataId($iMetadata) {
+	$sTable = 'metadata_lookup';
+	$sQuery = "SELECT document_field_id FROM " . $sTable . " WHERE id = ?";
+	$aParams = array($iMetadata);
+	
+	$res = DBUtil::getOneResultKey(array($sQuery, $aParams), 'document_field_id');
+	if (PEAR::isError($res)) {
+	    return false;
+	}
+	return $res;
+    }
+	    
+
+    function configure($aOptions) {
+        $res = parent::configure($aOptions);
+        if (PEAR::isError($res)) { 
+            return $res;
+        }
+        
+        $this->sIdMethod = KTUtil::arrayGet($aOptions, 'id_method', 'getId');
+        $this->sLabelMethod = KTUtil::arrayGet($aOptions, 'label_method');
+        if (empty($this->sLabelMethod)) {
+            return PEAR::raiseError(_kt('No label method specified.'));
+        }
+        $existing_entities = (array) KTUtil::arrayGet($aOptions, 'existing_entities');
+        
+        if (empty($this->value)) {
+            $this->value = array();
+            foreach ($existing_entities as $oEntity) {
+                $this->value[] = call_user_func(array(&$oEntity, $this->sIdMethod));
+            }
+        }
+
+	$this->iField = KTUtil::arrayGet($aOptions, 'field');
+	$this->iMasterId = KTUtil::arrayGet($aOptions, 'masterid');
+
+	// if we're the master, we have to build the dependancy array and store it as JSON
+	// also, include the javascript
+	if(KTUtil::arrayGet($aOptions, 'master', false)) {
+	    $this->bMaster = true;
+	    $this->aJavascript = array('resources/js/conditional_selection.js');
+
+	    $oFieldset = KTFieldset::get(KTUtil::arrayGet($aOptions, 'fieldset'));
+	    $aLookups = array();
+	    $aConnections = array();
+
+	    foreach($oFieldset->getFields() as $oField) {
+		$c = array();
+	      
+		foreach($oField->getEnabledValues() as $oMetadata) {
+		    $a = array();
+		    // print '<pre>';
+
+		    $nvals = KTMetadataUtil::getNextValuesForLookup($oMetadata->getId());
+		    if($nvals) {
+			foreach($nvals as $i=>$aVals) {
+			    $a = array_merge($a, $aVals);
+			    
+			    foreach($aVals as $id) {
+			      $field = $this->_getFieldIdForMetadataId($id);
+			      // print 'id ' . $id . ' is in field ' . $field . "<br/>";
+			      if(!in_array($field, $c)) {
+				$c[] = $field;
+			      }
+			    }
+			}
+		    }
+
+		    $aLookups[$oMetadata->getId()] = $a;
+		}
+		$aConnections[$oField->getId()] = $c;
+	    }
+	    
+	    //exit(0);
+
+	    $oJSON = new Services_JSON;
+	    $this->sLookupsJSON = $oJSON->encode($aLookups);
+	    $this->sConnectionsJSON = $oJSON->encode($aConnections);
+	}
+		
+
+        $new_vocab = array();
+        foreach ($this->aVocab as $oEntity) {
+            $id = call_user_func(array(&$oEntity, $this->sIdMethod));
+            $label = call_user_func(array(&$oEntity, $this->sLabelMethod));
+            $new_vocab[$id] = array($label, $oEntity->getId());
+        }
+        $this->aVocab = $new_vocab;
+    }
+
+    function getWidget() {
+        $bHasErrors = false;       
+        if (count($this->aErrors) != 0) { $bHasErrors = true; }
+
+	$this->sTemplate = 'ktcore/forms/widgets/conditional_selection';        
+        
+        $oTemplating =& KTTemplating::getSingleton();        
+        $oTemplate = $oTemplating->loadTemplate($this->sTemplate);
+
+        $unselected = KTUtil::arrayGet($this->aOptions, 'unselected_label');
+        if (!empty($unselected)) {
+            $vocab = array();
+            $vocab[] = $unselected;
+            foreach ($this->aVocab as $k => $v) {
+                $vocab[$k] = $v;
+            }
+            $this->aVocab = $vocab;
+            if (empty($this->value)) {
+                $this->value = '0';
+            }
+        }
+
+        if ($this->bMulti) {
+            $this->_valuesearch = array();
+            $value = (array) $this->value;
+            foreach ($value as $v) {
+                $this->_valuesearch[$v] = true;
+            }
+        }
+        
+        $aTemplateData = array(
+            'context' => $this,
+            'name' => $this->sName,
+            'has_id' => ($this->sId !== null),
+            'id' => $this->sId,
+            'has_value' => ($this->value !== null),
+            'value' => $this->value,
+            'options' => $this->aOptions,
+            'vocab' => $this->aVocab,
+	    'lookups' => $this->sLookupsJSON,
+	    'connections' => $this->sConnectionsJSON,
+	    'master' => $this->bMaster,
+	    'masterid' => $this->iMasterId,
+	    'field' => $this->iField,
+        );
+        return $oTemplate->render($aTemplateData);
+    }
+    
+
+
+}
+
+
diff --git a/plugins/ktcore/admin/fieldsets/conditional.inc.php b/plugins/ktcore/admin/fieldsets/conditional.inc.php
index 6c23ecb..31065f2 100644
--- a/plugins/ktcore/admin/fieldsets/conditional.inc.php
+++ b/plugins/ktcore/admin/fieldsets/conditional.inc.php
@@ -414,6 +414,16 @@ ordering!");
 
         $oField = $data['master_field'];
 
+	// remove all existing behaviors
+	$aFieldIds = array();
+	foreach($this->oFieldset->getFields() as $i) {
+	    $aFieldIds[] = $i->getId();
+	}
+
+	$sTable = KTUtil::getTableName('field_behaviours');
+	$aQuery = array("DELETE FROM $sTable WHERE field_id IN (" . DBUtil::paramArray($aFieldIds) . ")", $aFieldIds);
+	$res = DBUtil::runQuery($aQuery);		
+
         $res = KTMetadataUtil::removeFieldOrdering($this->oFieldset);
         $this->oFieldset->setMasterFieldId($oField->getId());
         $res = $this->oFieldset->update();
diff --git a/resources/js/conditional_selection.js b/resources/js/conditional_selection.js
new file mode 100755
index 0000000..df27143
--- /dev/null
+++ b/resources/js/conditional_selection.js
@@ -0,0 +1,172 @@
+// 'lookups' and 'connections' are produced by the master conditional widget
+var NOSELECTION = 'No selection.';
+
+function ConditionalSelection() {
+}
+
+function in_array(a, val) {
+    if(!a.length) {
+	return;
+    }
+    for(var i=0;i<a.length;i++) {
+	if(a[i] == val) {
+	    return true;
+	}
+    }
+    return false;
+}
+
+function getId(elm) {
+    if(elm.id.search('field_') != -1) {
+	return elm.id.substring('field_'.length);
+    } else if(elm.id.search('lookup_') != -1) {
+	return elm.id.substring('lookup_'.length);
+    }
+    return false;
+}
+
+ConditionalSelection.prototype = {
+    'initialize' : function(masterId) {
+	// make clones of the original nodes to keep the options in
+	var fieldLookups = {};
+	var current = {};
+	var lookups = eval('lookups_' + masterId);
+	var connections = eval('connections_' + masterId);
+
+	// initialize - build various tables
+	forEach(getElementsByTagAndClassName(null, 'is_conditional_' + masterId),
+		function(elm) {
+		    var fieldId = getId(elm);
+		    for(var i=0; i<elm.options.length; i++) {
+			var oElm = elm.options[i];
+			var lookupId = oElm.id.substring('lookup_'.length);
+			fieldLookups[lookupId] = {'parent':fieldId, 'value':oElm.innerHTML};
+
+			if(oElm.selected && oElm.value) {
+			    current[fieldId] = oElm.value;
+			}
+		    }
+		});
+
+	// the following function are defined inline, as they depend on the
+	// 'lookups' and 'connections' being specified above
+
+	function clearConnected(fieldId) {
+	    if(!fieldId in connections || !connections[fieldId].length) {
+		return;
+	    }
+	    for(var i=0; i<connections[fieldId].length; i++) {
+		var field = $('field_'+connections[fieldId][i]);
+		replaceChildNodes(field, OPTION(null, NOSELECTION));
+		field.disabled = true;
+		clearConnected(connections[fieldId][i]);
+	    }
+	}
+	
+
+	function clearInvalid(fieldId) {
+	    if(!fieldId in connections || !connections[fieldId].length) {
+		return;
+	    }
+	    
+	    var parentField = $('field_'+fieldId);
+	    var selectedId = getId(parentField.options[parentField.selectedIndex]);
+	    var options = lookups[selectedId];
+
+	    if(parentField.options[parentField.selectedIndex].innerHTML == NOSELECTION) {
+		clearConnected(fieldId);
+	    } else {
+		for(var i=0; i<connections[fieldId].length; i++) {
+		    var field = $('field_'+connections[fieldId][i]);
+		    var newOptions = [];
+		    var selected = null;
+
+		    for(var j=0; j<field.options.length; j++) {
+			var opt = field.options[j];
+			if(!(opt.innerHTML != NOSELECTION  && !in_array(options, getId(opt)))) {
+			    newOptions.push(opt);
+			}
+
+			if(j == field.selectedIndex && opt.id && in_array(options, getId(opt))) {
+			    selected = opt.id;
+			}
+		    }
+
+		    field.selectedIndex = 0;
+		    replaceChildNodes(field, null);
+		    
+
+		    for(var j=0; j<newOptions.length; j++) {
+			var opt = newOptions[j];
+			appendChildNodes(field, opt);
+			
+			if(selected != null) {
+			    if(opt.id && opt.id == selected) { // || j == 0 && field.selectedIndex == 0) {
+				field.selectedIndex = j;
+			    }
+			}			    
+		    }
+
+		    if(selected == null) {
+			field.selectedIndex = 0;
+			field.options[0].selected = 'selected';
+		    }
+
+
+		    clearInvalid(connections[fieldId][i]);
+		}
+	    }
+	}
+
+	// instead of clearing here, we remove the non-applicable options
+	// this should handle the case with existing selections
+	clearInvalid(masterId);	
+
+
+	function populateForSelection(selectedId) {
+	    if(selectedId in lookups) {
+		for(var i=0; i<lookups[selectedId].length; i++) {
+		    var lookupId = lookups[selectedId][i];
+		    var lookupInfo = fieldLookups[lookupId];
+		    
+		    var parent = $('field_' + lookupInfo['parent']);
+		    appendChildNodes(parent, 
+				     OPTION({'value':lookupInfo['value'], 'id':'lookup_' + lookupId}, 
+					    lookupInfo['value']));
+		    parent.disabled = false;
+		}
+	    }
+	}
+
+
+	forEach(getElementsByTagAndClassName(null, 'is_conditional_' + masterId), function(elm) {
+		    // check if this field connects to anything else
+		    var fieldId = elm.id.substring('field_'.length);
+		    if(fieldId in connections && connections[fieldId].length) {
+			var controller = true;
+		    }
+
+		    if(controller) {
+			connect(elm, 'onchange', 
+				function() {
+				    var selectedId = elm.options[elm.selectedIndex].id.substring('lookup_'.length);
+				    var touched = [];
+				    clearConnected(fieldId);
+				    populateForSelection(selectedId);
+				});
+		    }
+		});
+    }
+}
+
+
+
+addLoadEvent(function() {
+    var masters = getElementsByTagAndClassName('select', 'is_master');
+    for(var i=0; i<masters.length; i++) {
+	var elm = masters[i];
+	var masterId = getId(elm);
+	var d = new ConditionalSelection();
+	d.initialize(masterId);
+    }
+});
diff --git a/templates/ktcore/forms/widgets/conditional_selection.smarty b/templates/ktcore/forms/widgets/conditional_selection.smarty
new file mode 100755
index 0000000..c89a756
--- /dev/null
+++ b/templates/ktcore/forms/widgets/conditional_selection.smarty
@@ -0,0 +1,28 @@
+{if $master}
+<script type="text/javascript">
+var lookups_{$masterid} = {$lookups};
+var connections_{$masterid} = {$connections};
+</script>
+{/if}
+
+
+{if empty($vocab)}
+    <div class="ktInfoMessage"><span>{$context->sEmptyMessage}</span></div>
+{else}
+  <select name="{$name}" class="is_conditional_{$masterid}{if $master} is_master{/if}"
+    id="field_{$field}"
+    >
+    {if $options.initial_string}
+    <option value="">{$options.initial_string}</option>
+    {/if}    
+  {foreach item=lookup key=lookup_key from=$vocab}
+      {if is_array($lookup)}
+           <option value="{$lookup_key}" id="lookup_{$lookup.1}"
+	       {if ($value == $lookup_key)} selected="selected"{/if}>{$lookup.0}</option>
+      {else}
+           <option value="{$lookup_key}" 
+	       {if ($value == $lookup_key)} selected="selected"{/if}>{$lookup}</option>
+      {/if}
+  {/foreach}
+  </select>
+{/if}
diff --git a/templates/ktcore/metadata/conditional/conditional_admin_overview.smarty b/templates/ktcore/metadata/conditional/conditional_admin_overview.smarty
index 17aeb48..9e7a5eb 100644
--- a/templates/ktcore/metadata/conditional/conditional_admin_overview.smarty
+++ b/templates/ktcore/metadata/conditional/conditional_admin_overview.smarty
@@ -29,30 +29,6 @@ values in the other fields.  Only <strong>lookup</strong> fields can be added to
 </p>
 
 
-<p>
-    <a class="ktAction ktEdit ktActionDescribed" href="{addQS context=$context}fieldset_action=renameBehaviours{/addQS}">{i18n}Rename Behaviours{/i18n}</a>
-    <a href="{addQS context=$context}fieldset_action=renameBehaviours{/addQS}">{i18n}Rename Behaviours{/i18n}</a>
-</p>
-
-{if $oFieldset->getIsComplex()}
-<p>{i18n}The fieldset is currently designated as <strong>Complex</strong>.{/i18n} {i18n}Changing the conditional type set will remove all existing field
-ordering!{/i18n}</p> 
-
-
-<p><a href="{addQS context=$context}fieldset_action=changeToSimple{/addQS}"
-   class="ktAction ktActionDescribed ktEdit">{i18n}Change to simple{/i18n}</a>
-<a href="{addQS context=$context}fieldset_action=changeToSimple{/addQS}">{i18n}Change to simple{/i18n}</a></p>
-
-{else}
-
-<p class="descriptiveText important">{i18n}The fieldset is currently designated as <strong>Simple</strong>.{/i18n}</p> 
-
-<p><a href="{addQS context=$context}fieldset_action=changeToComplex{/addQS}"
-   class="ktAction ktActionDescribed ktEdit">{i18n}Change to complex{/i18n}</a>
-<a href="{addQS context=$context}fieldset_action=changeToComplex{/addQS}">{i18n}Change to complex{/i18n}</a></p>
-
-{/if}
-
 </fieldset>
 
 <br />
diff --git a/templates/ktcore/metadata/conditional/manageConditional.smarty b/templates/ktcore/metadata/conditional/manageConditional.smarty
index c878bc5..3bab28f 100644
--- a/templates/ktcore/metadata/conditional/manageConditional.smarty
+++ b/templates/ktcore/metadata/conditional/manageConditional.smarty
@@ -1,16 +1,11 @@
 <h2>{i18n}Manage conditional fieldset{/i18n}</h2>
 
 <p class="descriptiveText">{i18n}Conditional fieldsets allow you to restrict the options
-a user has for values in some fields based on the values in other fields.  There
-are two kinds of conditional fieldsets:  <strong>Simple</strong> and <strong>Complex</strong>
-.  Simple fieldsets should be sufficient for most things:  they allow you to say that 
+a user has for values in some fields based on the values in other fields, allowing you to say that 
 the values of one field are restricted to a certain subset of values if another field
 has a specific value.  For example, you could say that if the field "Street" is "Jeffrey", 
 then the field "Residents" must be one of "Jones","Smith" or "Friedman".{/i18n}</p>
 
-<p class="descriptiveText">{i18n}Complex fieldsets allow you to give far more detailed structure to
-your information:  The value of "Residents" can depend not only on "Street", but on
-how the user was allowed to select the specific street (given another field).{/i18n}</p>
 
 {* don't show warnings until the basics are done. *}
 
@@ -42,29 +37,6 @@ to complete{/i18n}: {$sIncomplete}</span>
 
 <h2>{i18n}Conditional type{/i18n}</h2>
 
-{if $oFieldset->getIsComplex()}
-<p>{i18n}The fieldset is currently designated as <strong>Complex</strong>{/i18n}</p> 
-
-{if ($oMasterField && empty($free_fields))}<p><a
-class="ktActionLink ktEdit"
-href="{$rootUrl}/plugins/ktcore/admin/manageConditionals.php?action=editComplexFieldset&fieldset_id={$oFieldset->getId()}">{i18n}Manage
-complex conditional{/i18n}</a></p>{/if}
-
-<form action="{$smarty.server.PHP_SELF}" method="POST">
-<input type="hidden" name="action" value="changeToSimple" />
-<input type="hidden" name="fFieldsetId" value="{$oFieldset->getId()}" />
-<input type="submit" name="submit" value="{i18n}Change to simple{/i18n}" />
-</form>
-
-{else}
-
-<p>{i18n}The fieldset is currently designated as <strong>Simple</strong>{/i18n}</p> 
-
-{if ($oMasterField && empty($free_fields))}<p><a
-class="ktActionLink ktEdit"
-href="{$rootUrl}/plugins/ktcore/admin/manageConditionals.php?action=editFieldset&fieldset_id={$oFieldset->getId()}">{i18n}Manage simple conditional{/i18n}</a>
-</p>
-{/if}
 
 <form action="{$smarty.server.PHP_SELF}" method="POST">
 <input type="hidden" name="action" value="changeToComplex" />