How to Resize the back ground image when scrolling the panel

[satclk]

Hi All,
Does any body know how to resize the back ground image in panel when
the panel is scrolling.

I am devolpng a whiteboard application for our LMS. I used c# applet
for this purpose. I create user control and embebed it as object in
aspx page. In my user control i have used the panel as drawing area.
When i draw Image (say rectangle) i make a rectangle object and add it
to panel. then i created bit map (size is panel size) draw the same
object in bit map and set that image as a back groung image in
panel.Otherwise i can not see the all the object were drawn coz user
control can not do tranperancy. I have make panel auto scroll property
to true.

My problem is when the panel is scrolling bit map image is not resize
with it. It genareate another bit map in same size and then drawn
images are repeat.

Does any one how to resize the that bit map image corresponding panel
size.

This code does not work. i tried with this one.

m_bmpSaved = new Bitmap (this.lpnlMainDrawing.Width ,
this.lpnlMainDrawing.Height);

help me.

Thank in advance
satclk