Simple VB 2005 question, please help

Hi,

For a university project i am developing a piece of open source software, TULP2G.  I have downloaded it and it builds in visual studio 2005 no problem. 

However, when I make changes to the tool, e.g. change the words on a form, i hit F5, it builds but does not show my edit to the program.  It just shows the original program. 

Any ideas would be VERY helpful.

Thanks,
Jon.