I need help working out a C# script with error CS0120

I have recently created the following script to make my character object move in either direction and also flip his sprite when moving left if facing right and visa versa

 //variables are being set
 public float maxspeed = 10f;
 bool facingright = true;




 // Use this for initialization
 void Start () {
 
 }
 
 // Update is called once per frame
 void FixedUpdate ()
 {
     float move = Input.GetAxis("horizantal");

     UnityEngine.Rigidbody2D.velocity = new Vector2(move * maxspeed, UnityEngine.Rigidbody2D.velocity.y);

     if (move > 0 && !facingright)
         Flip();
     else if (move < 0 && facingright)
         Flip();
 }
 //flips the player when they're facing left
 void Flip()
 {
     facingright = !facingright;
     Vector3 theScale = transform.localScale;
     theScale.x *= -1;
     transform.localScale = theScale;

 }

}

However i get error CS0120 and I can't figure out how to fix it.