I followed a tutorial for drawing graphics in an asp page but there is an error.(may look familiar)

Here's my page_Load code:

Response.ContentType = "image/jpeg";

Bitmap objBitmap;
Graphics objGraphics;

objBitmap = new Bitmap(200, 200);
objGraphics = Graphics.FromImage(objBitmap);

objGraphics.DrawLine(new Pen(System.Drawing.Color.Red), 0, 0, 200, 200);

objBitmap.Save(Response.OutputStream, ImageFormat.Gif);

objBitmap.Dispose();
objGraphics.Dispose();


the error is : the image " http://localhost:1653/Default.aspx \" cannot be displayed because of an error.


What is missing that is causing the problem?
Do I actually have to have an image load from someplace?
I'm not trying to do html text at the same time.