How do I use a " wait until " command in the arduino language?

I am trying to make quizbowl buzzers with the arduino.  I have gotten it to work with the nxt, but I want to use the arduino approach, because it is a waste to use the nxt for buzzers when I could be making robots with it... I haven't done much with arduino, in fact I have only looked at a few tutorials and downloaded the software.  But I need to know how to use a "wait until" command so that when a button is pressed a light lights up that on the control box containing the arduino (that corresponds with the button, or buzzer) that was pressed, and the light stays on (waits until) a clear button is pressed. 

I'm sorry if the wording is confusing.

I don't need a whole program, just the command, how to use it, and maybe a rough skeleton of the program