/// <summary>
/// Asynchronous update of the new CAPTCHA.
/// </summary>
/// <param name="l">length</param>
/// <returns></returns>
public ActionResult NewCaptcha(int l)
{
if (l < 4)
{
l = 4;
}
if (Request.IsAjaxRequest())
{
var captcha = CaptchaHelper.GeneratePartialCaptcha(Request.RequestContext, l);
return(JavaScript(string.Format(ReturnScript, captcha.Code, captcha.Image)));
}
return(Redirect(Request.UrlReferrer.AbsolutePath));
}