Movement in my terrain ?

I used this script for put movement in my terrain, but I only put movement in objects in my scene, used the mouse for move objects around this :

var target : Transform;
var distance = 10.0;

var xSpeed = 250.0;
var ySpeed = 120.0;

var yMinLimit = -20;
var yMaxLimit = 80;

private var x = 0.0;
private var y = 0.0;

@AddComponentMenu("Camera-Control/Mouse Orbit")
partial class MouseOrbit { }

function Start () {
    var angles = transform.eulerAngles;
    x = angles.y;
    y = angles.x;

    // Make the rigid body not change rotation
    if (rigidbody)
        rigidbody.freezeRotation = true;
}

function LateUpdate () {
    if (target) {
        x += Input.GetAxis("Mouse X") * xSpeed * 0.02;
        y -= Input.GetAxis("Mouse Y") * ySpeed * 0.02;

        y = ClampAngle(y, yMinLimit, yMaxLimit);

        var rotation = Quaternion.EulerAngles(y * Mathf.Deg2Rad, x * Mathf.Deg2Rad, 0);
        var position = rotation * Vector3(0.0, 0.0, -distance) + target.position;

        transform.rotation = rotation;
        transform.position = position;
    }
}

static function ClampAngle (angle : float, min : float, max : float) {
    if (angle < -360)
        angle += 360;
    if (angle > 360)
        angle -= 360;
    return Mathf.Clamp (angle, min, max);
}

I want walk in my terrain, how can I do this ?

Look at the CharacterController docs. I think that will be what you need.

Thanks a lot, I find this tutorial :

http://www.youtube.com/watch?v=EseaI3lPrKU