var vjan='';
function popup(url,nome,w,h){
	if (!vjan.closed && vjan.location) {
		vjan.location.href=url;
	}else{
		l=(window.screen.width/2)-(w/2)
		t=(window.screen.height/2)-(h/2)
		vjan=window.open(url,nome,'width='+w+',height='+h+',top='+t+',left='+l+',scrollbars=yes,fullscreen=no'); 
		if (!vjan.opener) vjan.opener = self;
	}
	if (window.focus){vjan.focus()}
}