Anybody know and want to help me through som VB express issues?

In a nut shell, the problem is this:
I know how to make something happen when I push a button. But how to create a "main loop"?

I have a small app that when I press the button, I can get 18 bytes of data from my PIC. But I need to get the data all the time, not just on a button press. Then if I press the stop button, well of course it stops.

this is what I think in the main:
Code:
do while getdata = 1
   get the data from the com port
   put the data in the text boxes
loop
Then my get data button would be :
Code:
open serial port
getdata = 1
stop button:
Code:
close serial port
getdata = 0
Of course there is more to the code then this, but I am stuck on not understanding the structure of things. Happy to post my code, of course I don't even know if the code I will post is all the code. I know where all I have written is.
I realize I should maybe post in a VB forum, but I know there are folks here that may be able to help, and I like it here better.