using interrupts

i'm working on getting a momentary push button to select various modes that a motor will perform. i'm unable to work it out. i started with the code from ladyada tutorial about blinky lights and being able to move through various states of blinkyness by using if and else. it's not working once the program gets into the loop. It doesn't notice the button push. i'm trying to work out how to integrate an interrupt to be able to trigger the 3 different modes. i'm new to all this, any help would be appreciated.

You almost certainly do not need an interrupt.

Why don't you post your code?

Can you tell us how exactly how you wired up your switch? Lack of pull-up or pull-down resistor is the most common problem the new comers have with interfacing switches when first starting out.