function popup(mylink, windowname, width, height, left, top)
{
if (!window.focus)return true;
var href;
if (typeof(mylink) == 'string')
   href=mylink;
else
   href=mylink.href;
window.open(href, windowname, 'width='+width+',height='+height+',scrollbars=yes,left='+left+',top='+top+',resizable=1');
return false;
}