Redirecting domain.com to www.domain.com

In global.asax:


protected void Application_BeginRequest(Object sender, EventArgs e)
{
    if (Request.Url.Authority.StartsWith("www"))
        return;

    string url = (Request.Url.Scheme
       + "://www."
       + HttpContext.Current.Request.Url.Authority
       + HttpContext.Current.Request.Url.AbsolutePath
    );

    Response.Clear();
    Response.Status = "301 Moved Permanently";
    Response.AddHeader("Location", url);
    Response.End();
}

Source: stackoverflow