function popup(mypage, myname, w, h, scroll)
 { 
var winl = (screen.width - w) / 2; 
var wint = (screen.height - h) / 2; 
winprops = 'height='+h+',width='+w+',top='+wint+',left='+winl+',scrollbars='+scroll+',resizable' 
win = window.open(mypage, myname, winprops) 
if (parseInt(navigator.appVersion) >= 4) { win.window.focus();
 } 
}