This newbie has text field problems

Hey ! I thank you about your advices.

I made all the corrections in my code and got a working one. But what I really want to do is not adding texts into one text field. I need to get the numbers which is written by users into text boxes and then use their inputs to make some calculations. (Like 3+6=9 ). When I assign numbers to variables Ican easily make calculations but what I really want is not that. the numbers should be entered by these text boxes. I think need to change “string” to “number” but when I do this I get error message. I am planning to use the calculation result in some other part of my code. I am wondering if using “return” function useful for me to get the number (the result) of calculation?

btw I wrote these and stuck afterall…

var inputone_num:Number;
var inputtwo_num:Number;

doit_btn.addEventListener(MouseEvent.CLICK, calculation);

function calculation(event:MouseEvent):void



I know I can not mix text and numbers together but I just tried.