Showing GUI on screen when in collider?

Hey everyone.

I watched a tutorial to show a texture as a GUI in the centre of the screen when you are in that objects collider, however nothing shows up? there is no errors so it must mean the code is working as correctly as it can?

I am also struggling to translate it into C# (pretty new but everything needs to be c# apparently)

Am i doing something wrong? thanks.

Jscript
#pragma strict

private var showGui : boolean = false;

var texturz : Texture;

function OnTriggerStay (Col : Collider)
{
	if(Col.tag == "Player")
	{
	
		showGui = true;
}

}

function OnTriggerExit (Col : Collider)
{
	if(Col.tag == "Player")
	{
	
		showGui = false;
}

}

function onGUIz ()
{
	if(showGui == true)
	{
		GUI.DrawTexture(Rect(Screen.width / 4.3, Screen.height /4, 1024, 1024), texturz);
	}


}

function onGUIz ()

should be

function OnGUI()

the whole thing in C#:

using UnityEngine;
using System.Collections;

public class ClassName : MonoBehaviour
{
    private bool showGui = false;

    public Texture texturz;

    void OnTriggerStay(Collider Col)
    {
        if (Col.tag == "Player")
        {

            showGui = true;
        }
    }

    void OnTriggerExit(Collider Col)
    {
        if (Col.tag == "Player")
        {

            showGui = false;
        }
    }

    void OnGUI()
    {
        if (showGui == true)
        {
            GUI.DrawTexture(new Rect(Screen.width / 4.3f, Screen.height / 4f, 1024f, 1024f), texturz);
        }
    }
}

function OnGUI ()
{
if (showGUI)
{
GUI.DrawTexture(Rect(Screen.width / 4.3, Screen.height /4, 1024, 1024), texturz);
}
}