function openPopup(url, width, height) {

    var x=(screen.width-width)/2;
    var y=(screen.height-height)/2;
	dialog=window.open(url,"","location=no,scrollbars=yes,resizable=yes,status=no,top=" + y + ",left=" + x + ",width=" + width + ",height=" + height);
	
	dialog.focus();

}