why isn't my txt script working?

ok so my script should explain what I want it to do, but for some reason It does not work when I click it! neather does the mouse over work

function OnMouseEnter ()
{
    renderer.material.color = Color.green;
}

function OnMouseExit ()
{
    renderer.material.color = Color.white;
}

function OnMouseUp()
{
    Application.LoadLevel(1);
}

make sure that your text is outside of what you have it in front of, and if that don't work than try this instead.

var isQuitButton = false;

function OnMouseEnter()
{
    //change the color of the text
    renderer.material.color = Color.green;
}

function OnMouseExit()
{
    //change the color of the text
    renderer.material.color = Color.white;
}

function OnMouseUp()
{
    //are we dealing with a Quit Button?
    if( isQuitButton )
    {
        //quit the game
        Application.Quit();
    }
    else
    {
        //load level
        Application.LoadLevel(1);
    }
}

agian make sure that your text is in front of it not inside.

If it's a GUIText try this:

guiText.material.color= Color.green;