function openWin(url, w, h) 
{ 

h = screen.height-220;
var top_pos = screen.height/2-h/2-30;

var winprop = "width=" + w + ",height=" + h +",status=yes,toolbar=no,menubar=no,location=no,scrollbars=yes,left="+(screen.width/2-w/2)+",top="+top_pos; 
openwin = window.open(url,'',winprop); 

//openwin = windows.open(url,null,"height=750,width=918,status=yes,toolbar=no,menubar=no,location=no,scrollbars=yes,left="+(screen_width/2-434)+",top=120");
}