add querystring to popup window script

 I can't seem to figure out how i would attach a query string to my static script. Ive tried a few things...onclientclick='<%# Eval("javascript:popUp(scanimage.aspx?)PONumber", "{0}") %>'  being one of them but that won't work. Just trying to get others input on this matter.
Thanks.

 
 
<Script Language="JavaScript">
function PopupWin(url,w,h){
///Parameters url=page to open, w=width, h=height
window.open(url, "external", "width=" + w +",height=" + h + ",resizable=no,scrollbars=no,status=no,location=no,toolbar=no,menubar=no");
}
</Script>   <asp:TemplateFi ...