Why there is an error when using Bitmap.save(Response.StreamOutPut,ImageFormat.Png)?

[Yok]

How to save png format to Response.OutPutStream?

Here's the error detail:
Exception Details: System.Runtime.InteropServices.ExternalException: A generic error occurred in GDI+.

Source Error:


Line 31:
Line 32: g.DrawString("Hi!",new Font ("Arial",23),new SolidBrush (Color.Blue ),3,3);
Line 33: bmp.Save (Response.OutputStream,ImageFormat.Png );
Line 34:
Line 35: