Web Forms :: Building A Form That Will Download Any File?

I have an idea of how to do what I have in mind, but I would prefer to ask for some advice just in case anyone can think of a better way.The idea is a simple application where administrators can upload any kind of file. Once the file is uploaded, they give out a username and password to a client, and the client will then access a private area where they will be able to view specific files available for them. ALL THIS IS DONE. My question is... because the browsers can process certain type of files (for instance a JPG or a PDF), they won't automatically prompt the client to save it on their computer, and they will open int he browser. I have solved this issue before by adding a few lines of code to the Response and modifying the content type, something like: Response.Clear(); Response.AddHeader("content-disposition", "attachment;filename=logo_large.gif"); Response.ContentType = "image/GIF"; Response.WriteFile(Server.MapPath(@"~/logo_large.gif")); Response.End();However, that would mean I'd need to change the content type for each file (JPG... GIF... PDF ... WORD FILE). So I'd need to find out the content type for each one, and dinamically change it. This way it would force the download for all files. Now... is there an easier way? Remember that I need to have many different type of files, if it was only JPGs for instance, it would be easy.