GUI text relative to screen?

I a GUI text to be at the top center but all the coding i did for it wont work.

#pragma strict

var offsetY : float =40;
var sizeX : float = 100;
var sizeY : float = 23;

function OnGUI() {

    GUI.TextArea(Screen.width/2-sizeX/2, offsetY, sizeX, sizeY)


please help quick!

GUI.TextArea takes a rect and a string

Change your code to

string TextToEdit;
TextToEdit = GUI.TextArea(new Rect (Screen.width/2-sizeX/2, offsetY, sizeX, sizeY),TextToEdit);