function abrirPopUp(URL, height, width)
{
	var altura = height;
	var anchura = width;
	var scroll = "no";
	if (height==null){  
		altura = 420;
		scroll = "yes";
	}
	if (width==null){ 
		anchura = 820;
		scroll = "yes";
	}
	var nombre		= "_blank"; 
	var atributos	= "channelmode=no,directories=no,fullscreen=no,height="+ altura +",left=0,location=no,menubar=no,resizable=no,scrollbars="+scroll+",status=no,titlebar=no,toolbar=no,top=0,width="+anchura+"";
	var reemplazar	= false;

	window.open(URL, nombre, atributos, reemplazar);
}