function janela(url,w,h,rolagem, status){

xpos=0;
ypos=0;

 if (screen){
 xpos= (screen.width - w)/2;
 ypos= (screen.height - h)/2;
 }
 var janela;

	if(rolagem == "no")
		janela="";
	else
		janela="";
	

 desktop=window.open(url+'?w=' + w + '&h=' + h,janela,'toolbar=no,location=no,top=' + ypos + ',left=' + xpos + ',directories=no,status=' + status + ',scrollbars=' + rolagem + ',menubar=no,resizable=no,width= ' + w + ',height=' + h + '' );
 desktop.focus();
}