anchor.diff:  			</c:when>
   			<c:otherwise>
   				<c:set var="cnum" value="${param.numberOfContainers}" />
  +				<%-- if numberOfContainers is not a number, set it to 0 --%>
  +				<c:catch var="e">
  +					<c:if test="${cnum>0}">
  +						<c:out value="${e}" />
  +					</c:if>
  +				</c:catch>
  +				<c:if test="${e!=null}">
  +					<c:set var="cnum" value="0" />
  +				</c:if>
   			</c:otherwise>
   		</c:choose>
  +
   		<%--create container for each container number --%>
   		<c:forEach var="cnum" begin="1" end="${cnum}">
   			<table class="topBorderOnly" cellspacing="0" cellpadding="3" width="100%" align="center" summary="" border="0">
  
positive.code: 			</table>
  			<br>
  		</c:forEach>
  
  		<table class="topBorderOnly" cellspacing="0" cellpadding="3" width="100%" align="center" summary="" border="0">
  			<tbody>
  				<tr>
  
negative.code: 									<td width="198" height="32">
  										<div align="right">
  											<input type="reset" value="Reset">
  											<html:submit />
  										</div>
  									</td>
  								</tr>
  