zooming into an image

Hi,

I have got a large picture box called picMain in the centre of my form. This picture box contains an image. Just to the left of this picture box there is another much smaller picure box called picFollow. When I move the mouse over the main picture box I would like to see a small area that the mouse is over appear in the smaller picture box "picFollow". I have seen this done before on the Windows2000 magnification program. Does anybody have some code ro something that I could learn from?

Thanks