function popup_window(url,w,h)
 {
  var width=w;
  var height=h;
  var toolbar='no';
  var location='no';
  var directories='no';
  var status='no';
  var menubar='no';
  var scrollbars='no';
  var resizable='no';
  var atts='width='+width+'show,height='+height+',toolbar='+toolbar;
  atts+=',location='+location+',directories='+directories+',status='+status;
  atts+=',menubar='+menubar+',scrollbars='+scrollbars+',resizable='+resizable;
  window.open(url,'win_name',atts);
 }