function showPopup(width, height,url,wname){

 var winl = (screen.width-width)/2;
 var wint = (screen.height-height)/2;
  
var size="width=" + width + ",height=" + height + ",left=" + winl + ",top=" + wint + ",menubar,toolbar,scrollbars,resizable";
var w=window.open("",wname,size);

var d = w.document;

d.location = url;
d.close();
}