Trapping MaxRequestLengthExceeded

protected void Application_BeginRequest(Object sender, EventArgs e)
{
    HttpRuntimeSection runTime = (HttpRuntimeSection)ConfigurationManager.GetSection("system.web/httpRuntime");
    // Approx 100 Kb(for page content) size has been deducted because the maxRequestLength proprty is the page size, 
    // not only the file upload size
    int maxRequestLength = (runTime.MaxRequestLength - 100) * 1024;

    //This code is used to check the request length of the page and if the request length is greater than
    //MaxRequestLength then retrun to the same page with extra query string value action=exception

    HttpContext context = ((HttpApplication)sender).Context;
    if (context.Request.ContentLength > maxRequestLength)
    {
        IServiceProvider provider = (IServiceProvider)context;
        HttpWorkerRequest workerRequest = (HttpWorkerRequest)provider.GetService(typeof(Http WorkerRequest));

        // Check if body contains data
        if (workerRequest.HasEntityBody())
        {
            // get the total body length
            int requestLength = workerRequest.GetTotalEntityBodyLength();
            // Get the initial bytes loaded
            int initialBytes = 0;
            if (workerRequest.GetPreloadedEntityBody() != null)
                initialBytes = workerRequest.GetPreloadedEntityBody().Length;
                
            if (!workerRequest.IsEntireEntityBodyIsPreloaded())
            {
                byte[] buffer = new byte[512000];
                // Set the received bytes to initial bytes before start reading
                int receivedBytes = initialBytes;
                while (requestLength - receivedBytes >= initialBytes)
                {
                    // Read another set of bytes
                    initialBytes = workerRequest.ReadEntityBody(buffer, buffer.Length);

                    // Update the received bytes
                    receivedBytes += initialBytes;
                }
                initialBytes = workerRequest.ReadEntityBody(buffer, requestLength - receivedBytes);
            }
        }
        // Redirect the user to the same page with querystring action=exception.
        context.Response.Redirect(this.Request.Url.LocalPath + "?action=exception");
    }
}