Instead of using scriplets you should use following way
keep ur variables in pageContext
<catalogue:bottom_nav page="ProductDefList.jsp" rowCount="${rowCount}" searchtext="${searchtext}" searchby="${searchby}" />
and keep ur varaibles <rtexprvalue>true</rtexprvalue> in *.tld file defination
and in catalogue tag's doStartTag method write this code for all evaluting variables
rowCount= ExpressionUtil.evalNotNull("rowCount",
"rowCount", rowCount, Object.class, this, pageContext);
hope this will solve ur problem...
Nandkishore