2d platfromer player controller will not jump

I have checked the inputs and can not get the jumping to work. The movement does work for left and right.`using UnityEngine; using System.Collections; using UnityEngine.UI;

public class SimpleController : MonoBehaviour {

 [HideInInspector] public bool facingRight = true;
 [HideInInspector] public bool jump = false;
 public float moveForce = 365f;
 public float maxSpeed = 5f;
 public float jumpForce = 400f;
 public Transform groundCheck;
 public Text countText;
 public Animator animator;

 private bool grounded = false;
 private Animator anim;
 private Rigidbody2D rb2d;
 private int count;

 void start ()
 {
     count = 0;
     SetCountText();
 }
 // Use this for initialization
 void Awake()
 {
     anim = GetComponent<Animator>();
     rb2d = GetComponent<Rigidbody2D>();

 }

 // Update is called once per frame
 void Update()
 {
     grounded = Physics2D.Linecast(transform.position, groundCheck.position, 1 << LayerMask.NameToLayer("Ground"));


     if (Input.GetButtonDown("Jump") && grounded)
     {
         jump = true;
     }
 }


 void FixedUpdate()
 {
     float h = Input.GetAxis("Horizontal");

     anim.SetFloat("Speed", Mathf.Abs(h));

     if (h * rb2d.velocity.x < maxSpeed)
         rb2d.AddForce(Vector2.right * h * moveForce);

     if (Mathf.Abs(rb2d.velocity.x) > maxSpeed)
         rb2d.velocity = new Vector2(Mathf.Sign(rb2d.velocity.x) * maxSpeed, rb2d.velocity.y);

     if (h > 0 && !facingRight)
         Flip();
     else if (h < 0 && facingRight)
         Flip();

     if (jump)
     {
         anim.SetTrigger("Jump");
         rb2d.AddForce(new Vector2(0f, jumpForce));
         jump = false;
     }

     animator.SetFloat("Speed", Mathf.Abs(h));
 }


 void Flip()
 {
     facingRight = !facingRight;
     Vector3 theScale = transform.localScale;
     theScale.x *= -1;
     transform.localScale = theScale;
 }
 void OntriggerEnter2D(Collider2D other)
 {
     if (other.gameObject.CompareTag ("PickUp"))
     {
         other.gameObject.SetActive(false);
         count = count + 1;
         SetCountText ();
     }
 }
 void SetCountText ()
 {
     countText.text = "Count; " + count.ToString();
 }

}`