validWhen Error

[satyamreddy reddybrother]

hello any body can help

iam using validwhen but iam not getting any client side validation
iam getting error like no ValidateWhen class found.is it necessary to add any lib to classpath

validation-rules.xml
<validator name="validwhen"
msg="errors.required"
classname="org.apache.struts.validator.validwhen.ValidWhen"
method="validateValidWhen"
methodParams="java.lang.Object,
org.apache.commons.validator.ValidatorAction,
org.apache.commons.validator.Field,
org.apache.struts.action.ActionMessages,
org.apache.commons.validator.Validator,
javax.servlet.http.HttpServletRequest"/>
and
validaion.xml
<form name ="/mcclist">

<field property ="Id" depends ="validwhen">
<arg0 key="arrsetup.arrid" resource="false"/>

<var>
<var-name>test</var-name>
<var-value>((issuerId == null)or(*this*!= null) </var-value>
</var>
</field>
</form>