function popup(mylink, venster, pw, ph)
{
if (! window.focus)return true;
var href;
if (typeof(mylink) == 'string')
   href=mylink;
else
   href=mylink.href;
w = window.screen.width;
h = window.screen.height- 20;
if(pw != 0 && ph !=0){
  w = (w - pw)/2;
  h = (h - ph)/2;
  window.open(href, venster, 'width='+pw+',height='+ph+',left='+w+',top='+h+',scrollbars=no');
}
else window.open(href, venster,'fullscreen,scrollbars=no');
return false;
}