You have to move the "viewport" using the .SetViewPort() method.

You should be able to find examples in MSDN.

>I did a big form where the user needs to scroll down to get further for input. I thought that the form will automatically scrolldown when the user is doing a tab from a visible field to a field that is in the hidden section, the system will automatically scroll down. It doesn't do that. How could we handle this ?