In your customer.jsp, call something like browse details(java script call)
<script language="javascript" type="text/javascript">
function callBrowseHierarchy(){
window.open("<%=contextpath%>/action.do","Browse","left=600,top=450,width=350,height=160,toolbar=0,resizable=0");
}
This will make a call to action class. Action class will thorow your generate.jsp as pop up window.
Thanks