Jumping, Grounded, Object Reference

I'm making a 2D movement script with JS and can't really figure out what I'm doing wrong. I keep getting "NullReferenceException: Object reference not set to an instance of an object" on different lines. I think I managed to fix it for var anim : Animator;, but now it's on line 55. (Which for some reason is line 57 here.) This is my script so far:

    var Speed : float = 80; //Max Vertical Movement Speed
    var FacingRight : boolean = false; // Is Character Facing Right?
    var FacingLeft : boolean = false; // Is Character Facing Left?
    var JumpForce : float = 20; // Jump Speed
    var anim : Animator; // The animator
    var Grounded : boolean = false;
    static var GroundRadius : float = 0.2;
    static var WhatIsGround : LayerMask;
    static var GroundCheck : Transform;
    
    function Start(){
    	anim = gameObject.GetComponent(Animator);
    }
    
    function parametercheck(){
    	anim.SetBool("FacingRight",FacingRight);
    	anim.SetBool("FacingLeft",FacingLeft);
    }
    
    function HorizontalMove(){
    	var move : float = Input.GetAxis("Horizontal");
    	anim.SetFloat("XSpeed",move);
    	var XAxisSpeed : float = anim.GetFloat("XSpeed");
    	var charscale : Vector3 = transform.localScale;
    	anim = GetComponent(Animator);
    	
    	rigidbody2D.velocity = Vector2(move * Speed, rigidbody2D.velocity.y);
    	
    	if(XAxisSpeed == 0){
    		parametercheck();
    		FacingRight = false;
    		FacingLeft = false;
    	}
    	if(XAxisSpeed > 0){
    		parametercheck();
    		FacingRight = true;
    		FacingLeft = false;
    	}
    	if(XAxisSpeed *Less than Symbol* 0){
    		parametercheck();
    		FacingRight = false;
    		FacingLeft = true;
    	}
    }
    function VerticalMove(){
    	anim.SetFloat("YSpeed", rigidbody2D.velocity.y);
    	if(Grounded && Input.GetKeyDown(KeyCode.Space)){
    		anim.SetBool("OnGround", false);
    		rigidbody2D.AddForce(new Vector2(0, rigidbody2D.velocity.y));
    	}
    }
    function FixedUpdate(){
    	Grounded = Physics2D.OverlapCircle(GroundCheck.position, GroundRadius, WhatIsGround);
    	anim.SetBool("Ground", Grounded);
    	HorizontalMove();
    	VerticalMove(); // Jumping and falling
    }

There's probably some other things I'm doing wrong too... Edit: The *less than symbol* part should have that there, but the bbcode messed it up.