[Flash CS3] action script 2.0 help

I have read the below link:

It is very useful that I would like to do something like this.

I would like to ask more,
If I want to create a input text box to let people to add data,
as we have a txt file to contains the data that load randomly,
how can i make this data to be add to the txt file that the data will become one of the quotes load randomly?

Thanks a lot~