Extremely simple Gui problem

Hello. I literally just started a new project and I Made a simple and quick gui script. The Problem is that the gui just won’t show. There are no errors either. Also I am using a 3.X version of unity.
Here is the script(Extremely Simple)

    function OnTriggerEnter(){
var Label1 : String = "Hello World";
GUI.Label(Rect(0,0,100,200), Label1);

}

GUI calls have to be used in the OnGUI() function, not ontriggerenter

if you want to do something like that, you need to do :

var show : boolean = false;

function OnTriggerEnter()
{
show = true;
}

function OnTriggerExit()
{
show = false;
}

function OnGUI()
{
if(show)
{
var Label1 : String = "Hello World";
GUI.Label(Rect(0,0,100,200), Label1);
}
}