BCE0005 unknow identifier 'rigidbody'

here is my code. i follow the tutorial on youtube about pick up object, but the unity show unknow identifier RigidBody, i don't know how to fix it.

var onhand : Transform;

function OnMouseDown () { GetComponent(RigidBody).useGravity = false;

this.transform.position = onhand.position;

this.transform.parent = GameObject.Find("FPSController").transform;

 this.transform.parent = GameObject.Find("FirstPersonCharacter").transform;

}

function OnMouseUp () {

 this.transform.parent = null;
 GetComponent(RigidBody).useGravity = true;

}