Request.URL always returns http even though SSL is enabled

[ultimo]

I have prepared an ASP.NET web application (ASP.NET V2.0) and I configured it in my IIS (V7.5). I used Request.Url.AbsoluteUri in my application and it works fine in my server. I deployed the web application on my client's server machine (2008 R2 Server). But in my client's environment Request.Url.AbsoluteUri always return http url even though they enabled SSL. Whether any IIS settings configured on my client's server machine? Please guide me