I am a little confused. I am assuming that by forum you mean form. I'm not sure how much you know about building forms and the stuff that make them work (usually php scripts). Seemingly 'simple' forms are wide open to abuse by idiot spammers and spam bots. You should really be considering building validation into your membership form. I think the best thing you could do is to look into using ABVFP v2. It is a wonderful little form building application that NavalDesign has built and it makes building forms very easy. It comes with an easy to follow tutorial. You can read about it and download it by
clicking here.
If you want to continue your way then you should try an advanced button which you will find in > Insert > Form > Advanced Button. This button is much more customisable in both appearance and function.
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The moment one definitely commits oneself, then providence moves too. All sorts of things occur to help one that would never otherwise have occurred. A whole stream of events issues from the decisions, raising in one’s favor all manner of unforeseen incidents and meetings and material assistance which no man could have dreamed would have come his way. Whatever you can do or dream you can, begin it. Boldness has genius, power and magic in it. Begin it now. (William Hutchinson Murray)