function ventana( url, w, h ) 
{
	window.open( url, "", "width=" + w + ",height=" + h + ",top=" + ((screen.height/2)-(h/2)) + ",left=" + ((screen.width/2)-(w/2 )) + ",resizable=no,status=no,scrollbars=yes" );
}

function ventanaSinScroll( url, w, h ) 
{
	window.open( url, "", "width=" + w + ",height=" + h + ",top=" + ((screen.height/2)-(h/2)) + ",left=" + ((screen.width/2)-(w/2 )) + ",resizable=no,status=no,scrollbars=no" );
}