anchor.diff:  <%@ taglib uri="http://struts.apache.org/tags-logic" prefix="logic"%>
   <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
   
  +<c:choose>
  +	<c:when
  +		test="${! empty chemicalAssociationForm.map.assoc.attachment.id }">
  +		<c:set var="style" value="" />
  +	</c:when>
  +	<c:otherwise>
  +		<c:set var="style" value="display:none" />
  +	</c:otherwise>
  +</c:choose>
  +<c:choose>
  +	<c:when
  +		test="${! empty chemicalAssociationForm.map.assoc.associatedElementA.composingElement.id }">
  +		<c:set var="ceStyleA" value="" />
  +	</c:when>
  +	<c:otherwise>
  +		<c:set var="ceStyleA" value="display:none" />
  +
  +	</c:otherwise>
  +</c:choose>
  +<c:choose>
  +	<c:when
  +		test="${! empty chemicalAssociationForm.map.assoc.associatedElementB.composingElement.id }">
  +		<c:set var="ceStyleB" value="" />
  +	</c:when>
  +	<c:otherwise>
  +		<c:set var="ceStyleB" value="display:none" />
  +	</c:otherwise>
  +</c:choose>
   <html:form action="/chemicalAssociation">
   	<table width="100%" align="center">
   		<tr>
  
positive.code: 											property="assoc.associatedElementB.compositionType"
  											onchange="getAssociatedElementOptions('compositionTypeB', 'entityTypeB', 'compEleB')">
  											<option value="" />
  											<option value="Nanoparticle Entity">
  												Nanoparticle Entity
  											</option>
  											<option value="Functionalizing Entity">
  												Functionalizing Entity
  											</option>
  										</html:select>
  									</li>
  									<li>
  
negative.code: 											property="assoc.associatedElementA.compositionType"
  											onchange="getAssociatedElementOptions('compositionTypeA', 'entityTypeA', 'compEleA')">
  											<option value=""></option>
  											<html:options name="associationCompositionTypes" />
  										</html:select>
  									</li>
  									<li>
  