Text box resize

alright this might be an easy answer but for some reason i can’t get it to work.

i have a text box that i want to set its width to the size of the stage width and the height 30 pixels less. and have it resize when i resize the movieclip.

here the code i’m using


Stage.scaleMode = "noScale";

//position content
var HPositioner:Number = (Math.round((Stage.width - 640) / 2));
var VPositioner:Number = (Math.round((Stage.height - 480) / 2));

function HPosition () {
           var HPositioner:Number = (Math.round((Stage.width - 640) /2));

		   setProperty(updateText, _width, Stage.width);
	
}

function VPosition () {
           var VPositioner:Number = (Math.round((Stage.height - 480) /2));

		   setProperty(updateText, _height, Stage.height - 30);
		  
}

HPosition();
VPosition();

i want the text to automatically fill out the new adjusted text box as well. am I doing this correctly with the code i have?