BCE0020 error with animation

I am trying to get a 2D sprite to look like it is walking through the animator controller using a speed parameter. I feel like I'm getting really close except this error "BCE0020: An instance of type 'UnityEngine.Rigidbody2D' is required to access non static member 'velocity'." popped up. Could anyone take a look at my script and help me out? I'm rather new to unity.

 #pragma strict
 
 public var maxJumps = 0; // maximum numer of jumps
 private var numJumps = 0; //number of current jumps
 
 public var moveSpeed = 0;
 
 private var facingRight = true; //initally sprite faces to the right
 
 private var isWalking : boolean;
 
 public var jumpheight = 0;
 
 var animator : Animator;
 
 
 function Start() {
 
 animator = GetComponent("Animator");
 
 }
 function Update () {
 
 
     var x;
     var y; 
 
 
 if (Input.GetKeyDown("space") && CanJump()){
     x = GetComponent(Rigidbody2D).velocity.x;
 
     GetComponent(Rigidbody2D).velocity = new Vector2(0, jumpheight);
 
     numJumps ++;
 }
 if (Input.GetKey (KeyCode.A))
  {
      
     y = GetComponent(Rigidbody2D).velocity.y;
     GetComponent(Rigidbody2D).velocity = new Vector2(-moveSpeed, y);
     animator.SetFloat("Speed", GetComponent(Rigidbody2D.velocity.x));
 
     if (facingRight) {
         Flip();
     
     }
     }
 if (Input.GetKey (KeyCode.D)) {
     y = GetComponent(Rigidbody2D).velocity.y;
     GetComponent(Rigidbody2D).velocity = new Vector2(moveSpeed, y);
 
     animator.SetFloat("Speed", GetComponent(Rigidbody2D.velocity.x));
 
 
     if (!facingRight) {
         Flip();
     
     }
 
 }
 }
 
 
 
 
 function OnCollisionEnter2D (coll : Collision2D)
 {
     if (coll.gameObject.CompareTag("Ground")) {
         numJumps = 0;
     }
     }
     function CanJump() {
     return numJumps < maxJumps;
     }
 
 
     function Flip() {
         var flipScale : Vector3;
         var rigidbody : Rigidbody2D;
 
         rigidbody = GetComponent(Rigidbody2D);
 
         flipScale = rigidbody.transform.localScale;
         flipScale.x *= -1; //flip horizontally
 
         rigidbody.transform.localScale = flipScale;
 
         facingRight = !facingRight; // now facing opposite direction
     }
 
 it says that         animator.SetFloat("Speed", GetComponent(Rigidbody2D.velocity.x)); is tripping the error. please help!