private void SaveProfilePicFile(long userId, HttpPostedFile file)
{
FileModule fileModule = new FileModule();
string filename = file.FileName;
string extension = System.IO.Path.GetExtension(file.FileName.ToLower());
if (extension != ".jpeg" &&
extension != ".jpg" &&
extension != ".png")
throw new Exception("You can only upload image files.");
Session["profile_pic_file"] = fileModule.saveProfilePicForUserId(userId, file.InputStream, file.FileName);
}