Adding vars to textfield

1

hey just simple code firing different functions upon onClick… how do I add my variables to a my error_txt dynamic text field, without having to write tons of code?! im from as2, and before I would just::: my_txt.text = myVar;
here’s my code::

var num:uint = 0;
var nextFunction:Array = new Array(first,second,third);
stage.addEventListener(MouseEvent.CLICK, Advance);
function Advance(e:MouseEvent):void
{
    if (num != nextFunction.length)
    {
        nextFunction[num]();
        num ++;
    }
    else
    {
        error_txt.text = "end of functions";
    }
}
function first():void
{
    error_txt.textField += num;
}
function second():void
{
    error_txt = num;
}
function third():void
{
    error_txt += num;
}

and hmm doesnt display my current num var.
Help!??? thanks