function popup(w,h,p,n)
{
var left = (screen.availWidth/2) - (w/2) - 5;
var top = (screen.availHeight/2) - (h/2) - 15;
window.open(p,n,'width='+w+',height='+h+',scrollbars=0,status=0, left='+left+', top='+top)
}