Show/hide GUI Texture

Hi, I’ve got a problem with showing GUI textures. In my game’s main menu, when I click the How to play button, I want it to show a GUI texture which tells how to play the game. I’m not a programmer so making scripts is kind of a new thing to me. Anyway, here’s my script:

var isHowtoButton = false;
var GUITexture = false;

function OnMouseDown()
{
renderer.material.color = Color.green;
if ( isHowtoButton )
{ guiTexture.enabled = true;
}
}

Check out the Unity doc on GUI.Button (and using it wrapped in an IF to do stuff on mousepush) and OnGUI