Uploading a File with Fileupload-Control

 Hi!
I am trying to upload a file using the Fileupload-Control. Here is my code.
   
 public Button hoch;
 public FileUpload comma;
  protected override void CreateChildControls()
        {
            base.CreateChildControls();

            Button hoch = new Button();
            hoch.Text = "Upload";
            hoch.Click += new EventHandler(hoch_ButtonClick);
            this.Controls.Add(hoch);

            FileUpload comma = new FileUpload();
          ...