Player cannot jump

Hey Guys. could you please help me because my player doesnt want to jump if I press a key. Thanks.

using UnityEngine; using System.Collections;

public class PlayerMove : MonoBehaviour {

 public float maxSpeed = 4;
 public float jumpForce = 550;
 public Transform groundCheck;
 public bool lookingRight = true;
 public LayerMask whatIsGround;
 
 private Rigidbody2D rb2d;
 private Animator anim;
 private bool IsGrounded = true;
 private bool Jump = false;

 void Start () {
     rb2d = GetComponent<Rigidbody2D>();
     anim = GetComponent<Animator>();
 }
 
 void Upate() {
     if (Input.GetButtonDown ("Jump") && IsGrounded) {
         Jump = true;
     }
 }

 void FixedUpdate() {
     float hor = Input.GetAxis ("Horizontal");
     anim.SetFloat ("Speed", Mathf.Abs (hor));
     rb2d.velocity = new Vector2 (hor * maxSpeed, rb2d.velocity.y);
     IsGrounded = Physics2D.OverlapCircle (groundCheck.position, 0.15F, whatIsGround);
     anim.SetBool("IsGrounded", IsGrounded);
     if ((hor > 0 && !lookingRight) || (hor < 0 && lookingRight))
         Flip ();
     if (Jump) {
         rb2d.AddForce(new Vector2 (0,jumpForce));
         Jump = false;    
     }
 }
 
 public void Flip() {
     lookingRight = !lookingRight;
     Vector3 myScale = transform.localScale;
     myScale.x *= -1;
     transform.localScale = myScale;
 }

}