Thanks for your responses, i hear what your saying about doing it all server side, that makes much more sense, although it's all written now and (nearly!) nicely working like this so, assuming MarkR is right that i've basically just written some javascript that the safari client doesn't like, it would be fantastic if i could just fix that error and then it would all be fine.
This also makes sense because i'm not bad at php but have never really programmed javascript, do you have any suggestions as to where might be the best place to seek help on my javascript problems?
Thanks very much again,
Dave