Way too short first off. ESPECIALLY as it's 9.3 mb. Should be 1 or 2 MAX.
"I couldn't add a replay button because if I did, the score wouldn't reset. Can someone tell me how to reset a text field?"
Well, sounds like at least you tried with this...Well maybe not. You should do research and figure out how to finish your games to what you think they could be.
How are you keeping your score? Obviously variables. So, let's say your score var is simply "score". And each time they get a question right it goes up one.
Well on the replay button heres an example of simple code to reset the score.
on (press){
_root.score==0;
_root.gotoAndStop (1);
}
For the frame number, of course it's wherever you want to replay from. For the _root.score, the score is your score variable.