anchor.diff:  					<td>
   						Existing Groups
   						<br/>
  +						<span id="bloodGroups">
   						<html:select property="existingGroups" multiple="multiple" size="8"
   							ondblclick="MenuSwapper.move($('nonselectedGroups'),$('selectedGroups'));"
   							styleId="nonselectedGroups" style="width: 200px;">
   							<html:optionsCollection property="existingGroups"/>
   						</html:select>
  +						</span>
  +						<span id="tissueGroups" style="display:none">
  +						<html:select property="existingGroups" multiple="multiple" size="8"
  +							ondblclick="MenuSwapper.move($('nonselectedGroups'),$('selectedGroups'));"
  +							styleId="nonselectedGroups" style="width: 200px;">
  +							<html:optionsCollection property="existingTissueGroups"/>
  +						</html:select>
  +						</span>
   					</td>
   					<td style="vertical-align: middle;" id="menuSwapperButtons">
   						<b id="baselineButtons">
  
positive.code: 
  <div>
  	<b>Specimen Type:</b>
  	<html:select property="specimenType" styleId="platform">
  		<html:optionsCollection property="existingSpecimenTypes"/>
  	</html:select>
  </div>
  
negative.code: 			$('covariates').hide();
  		}
  	},
  	'changeSpecimen' : function(el)	{
  		//clear all selections, hide the existing options and show the correct ones
  		MenuSwapper.saveMe( $('selectedGroups'),$('nonselectedGroups') ); //select them all
  		MenuSwapper.move($('selectedGroups'),$('nonselectedGroups')); //move them back
  		
  		//clear the baseline
  		MenuSwapper.move($('selectedBaseline'),$('nonselectedGroups'));
  		
  		if(el.selectedIndex != 0)	{
  			//tissue
  			$('bloodGroups').hide();
  			$('tissueGroups').show();
  		}
  		else	{
  			$('tissueGroups').hide();
  			$('bloodGroups').show();		
  		}
  		
  	},
  	'validate': function()	{
  		if($('analysisName').value == "")	{
  			alert("Please enter an Analysis Name");
  