Hi,
I looked at this earlier today and on the basis that you are new to VB this is quite advanced code for you to be dealing with? The reason why it says Handleoverflow is not declared is because of exactly that. There is nowhere in your code that declares a function or subroutine called Handleoverflow and therefore your AddHandler statement cannot ever work.
There is no way for me to guess what Handleoverflow is supposed to do and therefore its probably impossible for me or anyone else to help you.
My advice would be to try and obtain the other code which contains the Handleoverflow routine that you say is in another project and then we may be able to help.
Good luck,
Ian