Canon A720 IS. I'm trying to set the ISO to 100. The manual shows how to press the func. set

Question

I'm trying to set the ISO to 100. The manual shows how to press the func. set button and then using the up/down outer ring scroll up and highlight iso and make the change. My camera won't go up to the iso icon, it will only allow me to highlight the square box the L and the quarter-circle icon directly above it. Can you tell me how to change the iso setting?