function ir_a(url){
	document.location.href=url;
	}
function popup(url,titulo,x,y){
	if (x==""){
		x=300;
	}
	if (y==""){
		y=400;
	}
	window.open(url, titulo ,'toolbar=0, status=0, resizable=0,scrollbars=1,width='+x+' ,height= '+y);
}