Hi,
The following is the url tag usage
<c:url var="newurl" value="/catalog" >
<c:param name="Add" value="${bookId}" />
</c:url>
<strong><a href="${newurl}">
Consider bookId value is 20.
The above url tag creates the variable "newurl" with the following value
CurrentPageAddress/catalog?Add=20
If you want to add one more parameter you need to add one more <param> tag inside the url tag
If you have any queries please let me know or send a mail to me at doubtplz@gmail.com
Thanks & Regards
Santhosh Reddy Mandadi