i cant see the constrainst in rigidbody2d need help

this is my script by the way it is C# using UnityEngine; using System.Collections;

public class PlayerController : $$anonymous$$onoBehaviour {

 public float moveSpeed;
 public float jumpHeight;
 float moveVelocity;
 private bool grounded = false;

 // Use this for initialization
 void Start()
 {
     
 }

 // Update is called once per frame
 void Update()
 {

     if (Input.Get$$anonymous$$eyDown($$anonymous$$eyCode.Space) ||
        Input.Get$$anonymous$$eyDown($$anonymous$$eyCode.UpArrow))
     {
         if (grounded)
         {
             GetComponent<Rigidbody2D>().velocity = new Vector2(GetComponent<Rigidbody2D>().velocity.x, jumpHeight);
         }
      }
     moveVelocity = 0;

     //movement
     if (Input.Get$$anonymous$$ey ($$anonymous$$eyCode.A) ||
         Input.Get$$anonymous$$ey ($$anonymous$$eyCode.LeftArrow))
     {
         moveVelocity = -moveSpeed; //move left
     }

     if (Input.Get$$anonymous$$ey($$anonymous$$eyCode.D) ||
         Input.Get$$anonymous$$ey($$anonymous$$eyCode.RightArrow))
     {
         moveVelocity = moveSpeed; //move right
     }
     GetComponent<Rigidbody2D>().velocity = new Vector2(moveVelocity, GetComponent<Rigidbody2D>().velocity.y);
 }
 //check grounded
 void OnTriggerEnter2D()
 {
     grounded = true;
 }
 void OnTriggerExit2D()
 {
     grounded = false;
 }

}