anchor.diff:                          </html:select>
                         </td>
                         <td valign="top" align="center">
  -                        <span id="operandEditSpan">
  +                        <span id="operandEditSpan0">
                             <html:text property="attributeValue"/><br/>
                             <%-- might want to show up arrow --%>
                             <c:if test="${!empty attributeOptions}">
  
positive.code:                     </c:when>
                      <c:otherwise>
                        <td valign="top">
                          <html:select property="attributeOp" onchange="updateConstraintForm(this.form)">
                            <c:forEach items="${attributeOps}" var="attributeOp">
                              <html:option value="${attributeOp.key}">
                                <c:out value="${attributeOp.value}"/>
  
negative.code:         <!--
          
          var fixedOps = new Array();
         
          /***********************************************************
           * Called when user chooses a constraint operator. If the
           * user picks an operator contained in fixedOptionsOps then
           * the input box is hidden and the user can only choose
           **********************************************************/
          function updateConstraintForm(index, attrOpElement, attrOptsElement, attrValElement)
          {
            if (attrOptsElement == null)
              return;
          
            for (var i=0 ; i<fixedOps[index].length ; i++)
            {
              if (attrOpElement.value == fixedOps[index][i])
              {
                document.getElementById("operandEditSpan" + index).style.display = "none";
                attrValElement.value = attrOptsElement.value; // constrain value
                return;
              }
            }
            
            document.getElementById("operandEditSpan" + index).style.display = "";
          }
          
          /***********************************************************
           * Init attribute value with selected item and hide input box if
           * required
           **********************************************************/
          function initConstraintForm(index, attrOpElement, attrOptsElement, attrValElement)
          {
            if (attrOptsElement == null)
              return;
            
            attrValElement.value = attrOptsElement.value;
            updateConstraintForm(index, attrOpElement, attrOptsElement, attrValElement);
          }
          
          //-->
          </script>
          
          <script type="text/javascript">
          <!--
          
          fixedOps[0] = new Array();
          <c:forEach items="${fixedOptionsOps}" var="op" varStatus="status">
            fixedOps[0][${status.count}] = "<c:out value="${op}"/>";
          </c:forEach>
          
          //-->
          </script>
  