Trouble with Text Fields

Hi, I’m trying to figure out how to code text fields in Flash (and I’m new to Action Script, at least in going beyond basic interactivity). Problem is, this is for a client and I’m on a deadline.

The user has to type a particular number in a textfield, then a particular number in a second textfield. The numbers are automatically added and in a third textfield, the answer is displayed. There are other examples in the exercise where four or five numbers have to be added, and in one case a couple numbers are multiplied.

Does anybody have any ideas?