Button Work As A Switch

This is could be a noob question, but I don't know where to look for answer.
I wanted to create form with a button that checks a boolean value and computes depend on the value. At the end of the click, it should revert the boolean value. ie, if it's true, reverts to false. or the reverse....works like a switch

something like
protected bool myBool = true;
......
if(myBool){process 1....myBool = false;}elseprocess 2....myBool = true;}

Some how, it works on the first click. process1 got processed and boolean changed to false. But it doesn't work on the second click..the handler was never get called again.
What's the problem?.