zoliky, this is the third thread you've made about your groups, and problems you're having. I'm sure people are more then happy to help, but it would be a lot easier if you kept all questions in one thread.
From what I can see you're trying to run functions depending on what option is checked. If option 1 is selected you want to show users, or if option 2 is select you want to delete the group. The simple way of doing this would be to insert MySQL queries into the IF statement, like you've nearly already done.
If you're trying to do a 'confirm' message, asking if the user wants to delete the group, then you'll need to use Javascript, as its client-side.
