How to make a button influence a dynamic textfield?

programming flash
1

So, I have two textfields (txt_name and txt_description), as well as a button (btn_pasteasplaintext). I’m trying to make it so when you hover over the button, both the text fields change. This is what I have so far:

btn_pasteasplaintext.onRollOver = function() {
    txt_name.Text = "Paste as plain text";
}

It doesn’t seem to work…