How to get the body of a HTTP Request using C#

gistfile1.cs

private string GetDocumentContents(System.Web.HttpRequestBase Request)
{
    string documentContents;
    using (Stream receiveStream = Request.InputStream)
    {
        using (StreamReader readStream = new StreamReader(receiveStream, Encoding.UTF8))
        {
            documentContents = readStream.ReadToEnd();
        }
    }
    return documentContents;
}

There is no .InputStream available on my Request :(