function zoom(u,n,w) { 
pag= "/zoom.asp?u="+u+"&n="+n;
h = 600;
w = +w;
str = "screenX=0,screenY=0,width="+ w +",height=" + h + ",status=no,toolbar=no,menubar=no,location=no,scrollbars=yes";
window.open (pag,'zoom', str);
}