i would like to know how to make a pop-up come up after a user has followed a certain route.

For instance, I got 4 main buttons, which are divided by 5 buttons. I'd like to create a little script that when after the user clicked on the 5 buttons from left to right, a pop-up shows up which will provide help. I know how to create a pop-up and I know how to give a proper lay-out to it. All I don't know is how to make the script which will track if the user has clicked on the 5 headers and will then open the pop-up.

thanks in advance for the help.