Integration of a progress bar

Hello there,
I have a menu to my game, and the menu has two bottons that takes you to two different scenes (levels), and I want to have a loading bar between the menu and the scenes, I have a progressing bar script that I have found on the forums here, and it works fine, but I dont know where should I place it in my menu script, do I need to make a new scene with the progressing bar or is it possible to place the code inside the menu script?
The progressing bar script:

var progress : float = 0;
var pos : Vector2 = new Vector2(20,40);
var size : Vector2 = new Vector2(60,20);
var progressBarEmpty : Texture2D;
var progressBarFull : Texture2D; 
function OnGUI()
{
GUI.DrawTexture(Rect(pos.x, pos.y, size.x, size.y), progressBarEmpty);
GUI.BeginGroup(new Rect (pos.x, pos.y, size.x * Mathf.Clamp01(progress), size.y));
GUI.DrawTexture(new Rect(0, 0, size.x, size.y), progressBarFull);
GUI.EndGroup();
} 
function Update()
{
    progress = Time.time * 0.05;  
}

And the GUIBotton in the menu script that opens the first scene:

if (GUI.Button(Rect(200,360,222,49),btnProjects, customButton))
    	Application.LoadLevel("Level1");

a little old… but looks like it covers it off…

I tried to use that, but it didnt work for me. I am very new to coding you know…
I was just wondering how I use that progressing bar I have posted in my script?

I suppose you want the progress bar to show the loading state of the level?

What LeftyRighty said is exactly what you need, however you would need unity pro as it uses LoadLevelAsync.
If you use a simple LoadLevel call you cant really display anything else than 0% or 100% cause thats the only info you get :confused:
Of course you could increase the percentage every frame but that doesnt really show the progress of the level load.

What I need is something between my menu and the scene, cuz it takes some time to load the scene.

Anybody? I did use LoadLevelAsync, but it doesnt show the progressing bar, is there any other way to make a progressing bar? The point is that the user sees that it is working and trying to open another level…