Basic flood protection scripts use a format like the one shown. You basically use a variable to determine if you recently reacted to the trigger. If the variable is set, you don't react. If the variable is not set, you do react. You simply set the variable to unset within a certain period of time (the -u part). It doesn't matter what you set the variable to - 1 in the script above - just as long as it is set to something. When the timer runs out, you'll react to the script's trigger again. You can, of course, modify it in a variety of ways such as making it so you react X times in a certain amount of time and then stop reacting - instead of only once in the time period. It all depends on what your needs are. But the basic format is usually where you would start.
