After change to below html:button code, page 404 showed in the pop up window. The <%=PopUp_url%> is not replace by the actual value when i view the properties of the PopUp Window. It is still <%=PopUp_url%>/Pop_up.jsp.
You can't "embed" a JSP expression in a literal value when it comes to custom tag attributes that take runtime expressions. In other words, instead of "literal <%= expr %> literal", it must be '<%= "literal" + expr + "literal" %>'.
Note: If escaping the single quotes with "\" doesn't work, try using two single quotes, i.e. "SearchPopup(''" + ... I'm not quite sure which form the JSP parsing will accept. [ December 09, 2004: Message edited by: Junilu Lacar ]