Simplest thing to do (i.e. not requiring us to do anything!) would be to type your answer in a program that features a spell checker - such as Word - and then copy'n'paste it into the Answerbank.
WendyW et al -- if you *really* want to spell check before posting, and don't have Word (or similar) you could open a Hotmail account (or similar), type your reply there and use their Spell Check. Or.... I hardly dare suggest it... invest in a dictionary!
Needless to say, if there are any mistakes I will do my best to step in and edit your replies as soon as possible.