function open_popup(pag,nombre,w,h)
{
var alto = screen.height / 2 - 200;
var ancho = screen.width / 2 - 280;

car = "toolbar=no,width="+w+",height="+h+",directories=no,status=no,menubar=no"
car = "top=" + alto + ",left=" + ancho + ",screenX=" + ancho + ",screenY="
+ alto + "," + car
window.open(pag,nombre,car)
}


function checkEmail(email) {
if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(email)) {
	return (true)
}
return (false)
}