iphoto image renumbering

Sorry if this is an old question couldn't find any previous info on it, I have downloaded photo's from my canon camera into iphoto but forgot to zero image numbers, now having put a couple of cards full into iphoto an and album I have dragged photo's into a proper order but burning to disc they are all mixed up, can I renumber images so when burnt they are recorded on dvd disc in order of the event ( ie a wedding ) any help would be appreciated,
if you can keep it simple as I am a bit of a computer novice still,
thanks stefos

You can use name changer to do it outside of iPhoto.

I don't know of any way to do it within iPhoto. Perhaps others will.