function Pop(arg, w, h){
	var file = 'popwindow.php';
  var URL = arg != undefined
    ? file + '?page=' + arg
    : file;
	eval("window.open(URL, '', 'toolbar=0,scrollbars=no,location=no,statusbar=0,menubar=0,resizable=0,width="+w+",height="+h+",left="+(screen.availWidth-w)/2+",top="+(screen.availHeight-h)/2+"');");
}