Set a GUI as false in the beginning

Is there a statement to put in the following script for example to make sure that it is False?

function OnGUI () {
// Make a background box
GUI.Box (Rect (10,10,100,90), “Loader Menu”);

// Make the first button. If it is pressed, Application.Loadlevel (1) will be executed
if (GUI.Button (Rect (20,40,80,20), "Level 1")) {
	Application.LoadLevel (1);
}

// Make the second button.
if (GUI.Button (Rect (20,70,80,20), "Level 2")) {
	Application.LoadLevel (2);
}

}

create a variable with which you check if the GUI should be enabled:

var drawGUI : boolean = false;

function OnGUI () { 

if(drawGUI){
GUI.Box (Rect (10,10,100,90), "Loader Menu");
if (GUI.Button (Rect (20,40,80,20), "Level 1")) {
    Application.LoadLevel (1);
}
if (GUI.Button (Rect (20,70,80,20), "Level 2")) {
    Application.LoadLevel (2);
}
}

as long as drawGUI is false, it won’t display the GUI. if you change it to true, it will be displayed.