Código PHP:
<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
function popUp1(URL) {
ventanita= window.open(URL, "ventanita", 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=456,height=400,left=314,top=210');");
}
// End -->
y el link:
<a href=javascript:popUp1('popupprod.php')>link</a>