Upper case function in index?

Hi, there, I assume some of you must experience the same situation. I need building an index upon people's name. I would like sort them in the order of either upper case or lower while name field allows mix-cased. I can not find a way in Informix to do it so I have to add a column of single-cased name for sorting purpose only. It is kind of waste, isn't it? Can any of you out here shed a light on the issue? Thank you in advance. Sims xhsims@erols.com