Character Rotation on the Touch of a Button

Sorry I wasn't specific enough. What I wanted was my character to do a backflip on the touch of a button. Only when grounded equals true. Here is my script. I have already made an input for backflip. Its positive button is left alt. PS I'm very new to scripting.

var moveSpeed = 3.0;

var turnSpeed = 3.0;

var jumpSpeed = 35.0;

private var grounded : boolean = false;

//Standard Moving Actions

function Update ()

    {
        var controller : CharacterController = GetComponent(CharacterController);

        transform.Rotate(0, Input.GetAxis ("Horizontal") * turnSpeed, 0);

        var forward = transform.TransformDirection(Vector3.forward);

        var curSpeed = moveSpeed * Input.GetAxis ("Vertical");

        controller.SimpleMove(forward * curSpeed);

        if(Input.GetButtonDown("Jump"))
    {
        transform.position+= transform.up * jumpSpeed * Time.deltaTime;
    }

    }

    //In Air Actions
    if(Input.GetButtonDown("Jump"))
    {
        grounded = true;
    }

    @script RequireComponent(CharacterController)

You could use an animation

This requires more explination than I think fits well in a forum

This Unity learn section should get you going though. It talks about setting up and controlling your animator and as I recall it uses an example of jumping. It does get into the scripting aspect as well