This script will do it but the only problem is that you have to hard code them into the script yourself. I could make something a bit more complex that will do the job for you but i cba. I have given you some examples of how to hard code them in, you just use the first 2 lines and they must match up to the on you are changing it to. I hope you like it.
code:
var original = new Array("dont","cant","wont");//what you are changing from
var changed = new Array("don't","can't","won't");//what you are changing to
function OnEvent_ChatWndMessageSent(ChatWnd,Message){
for(i in original){
Message = Message.replace(RegExp(original[i],"gi"),changed[i]);
}
return Message;
}
EDIT: thanks roflmao for fixing me up, teaches me right for writing scripts straight into a post
EDIT2: fixed the problem that mattike pointed out on the second page. hopefully i have learned my lesson now