Right now I'm trying to create a gliding jump, wherein if a player holds the control button during a jump the character will fall slower. Here is the code, which at the moment is crashing Unity consistently.

var Health = 0;
var walkSpeed : float = 20.0;
var gravity = 20.0;
private var moveDirection : Vector3 = Vector3.zero;
private var charController : CharacterController;
var jumpSpeed = 2;


function Start()
{
    charController = GetComponent(CharacterController);
    animation.wrapMode = WrapMode.Loop;
}


function Update ()
{
    if(charController.isGrounded == true)
    {
        if(Input.GetAxis("Vertical") > .1)
        {
            //if(Input.GetButton("Run"))
            //{
                //animation.CrossFade("run");
               // walkSpeed = 20;
           // }
           // else
            //{
                //animation["walk"].speed = 1;
                //animation.CrossFade("walk");
                //walkSpeed = 20;
            //}
        }
        else if(Input.GetAxis("Vertical") < -.1)
        {
            //animation["walk"].speed = -1;
            //animation.CrossFade("walk");
           // walkSpeed = 20;
        }
        else
        {
            //animation.CrossFade("idle");
        }

        // Create an animation cycle for when the character is turning on the spot
        if(Input.GetAxis("Horizontal") && !Input.GetAxis("Vertical"))
        {
            //animation.CrossFade("walk");
        }


        transform.eulerAngles.y += Input.GetAxis("Horizontal");

        // Calculate the movement direction (forward motion)
        moveDirection = Vector3(0,0, Input.GetAxis("Vertical"));
        moveDirection = transform.TransformDirection(moveDirection);

            if (Input.GetButton ("Jump")) {

            moveDirection.y = jumpSpeed;                        

            } //End Jump

    }

    moveDirection.y -= gravity * Time.deltaTime;
    charController.Move(moveDirection * (Time.deltaTime * walkSpeed));



                if (Input.GetButton ("Glide") && charController.isGrounded != true) {   
                    Debug.Log("Glide button Hit");
                    rigidbody.AddForce (moveDirection.y * 10);

                }//End Glide


}