limit switch

I recived a vex starter kit for christmass. and i built the squarebot and then replaced the buper for the limit switch to make it not go off the table and it does not due anything. i made it equil limit==0 when down (keep going)and when limit==1 (stop) it did not work how would i set this up.:confused:

see this thread: https://vexforum.com/t/two-or-four-bumper-program-in-easy-c/14020/1