problem in using asp.net stream graphic and image

[miladhatam]

hi
i want to put the name of my site in corner of my images
i've used from graphics and bitmap class and i have no problem with
putting the text
but it make problem with other works in my page
for example :
//-------------------------- begin
Bitmap bitMapImage = new
System.Drawing.Bitmap(Server.MapPath("image/" + 2 + ".jpg"));

Graphics graphicImage = Graphics.FromImage(bitMapImage);
graphicImage.SmoothingMode = SmoothingMode.AntiAlias;
Rectangle rect = new Rectangle(1,1,50,50);

graphicImage.DrawString("irankohan.com", new Font("Arial", 12,
FontStyle.Bold), SystemBrushes.WindowText, new Point(13, 27));
graphicImage.DrawArc(new Pen(Color.White, 3), 90, 235, 150, 50, 0,
360);
Response.ContentType = "image/jpeg";

bitMapImage.Save(Response.OutputStream, ImageFormat.Jpeg);
//--------------------------- end
Label lb = new Label();
lb.Text = "milad";
Controls.Add(lb);

i wanna show information about the picture dynamically but it can't
be shown
why ?