function winpop(w,h,url,name) {
screenW = screen.width;
screenH = screen.height;
w_pos=Math.round(screenW/2) - (w/2);
h_pos=Math.round(screenH/2) - (h/2);
string="height="+h+",width="+w+",top="+h_pos+",left="+w_pos+",menubar=no,toolbar=no,status=no,location=no,resizable=no,directories=no,scrollbars=yes";
window.open(url,name,string);
}