how to make a character a long jump in unity ?

using UnityEngine; using System.Collections;

public class PlayerControl : MonoBehaviour {

 public float moveSpeed;
 private float moveSpeedStore;
 public float jumpForce;
 public float jumpTime;
 private float jumpTimeCounter;

 public float speedMutiplayer;

 public float speedIncreaseMilestone;
 private float speedIncreaseMilestoneStore;
 private float speedMilestoneCount;
 private float speedMilestoneCountStore;

 private Rigidbody2D myRigibody;

 public bool grounded;
 public LayerMask whatIsGrounded;
 public Transform groundCheck;
 public float groundCheckRadius;

 public GameManager theGameManager; 
 private bool stoppedJumping;
 private bool canDoubleJump;

 private Animator myAnimator;
 float deltaTime = 0.0f;

 public AudioSource DeathSound;

 // Use this for initialization
 void Start () {

     myRigibody = GetComponent<Rigidbody2D>();
     myAnimator = GetComponent<Animator>();


     jumpTimeCounter = jumpTime;
     speedMilestoneCount = speedIncreaseMilestone;

     moveSpeedStore = moveSpeed;
     speedMilestoneCountStore = speedMilestoneCount;
     speedIncreaseMilestoneStore = speedIncreaseMilestone;

     stoppedJumping = true;

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

     UptCode();
 }

 void OnCollisionEnter2D(Collision2D other)
 {
     if (other.gameObject.tag == "killbox")
     {
         theGameManager.RestartGame();
         moveSpeed = moveSpeedStore;
         speedMilestoneCount = speedMilestoneCountStore;
         speedIncreaseMilestone = speedIncreaseMilestoneStore;

         DeathSound.Play();
     }
 }


 void OnGUI()
 {
     int w = Screen.width, h = Screen.height;

     GUIStyle style = new GUIStyle();

     Rect rect = new Rect(0, 0, w, h * 2 / 100);
     style.alignment = TextAnchor.UpperLeft;
     style.fontSize = h * 2 / 100;
     style.normal.textColor = new Color(0.0f, 0.0f, 0.5f, 1.0f);
     float msec = deltaTime * 1000.0f;
     float fps = 1.0f / deltaTime;
     string text = string.Format("{0:0.0} ms ({1:0.} fps)", msec, fps);
     GUI.Label(rect, text, style);
 }

 public void UptCode()
 {
     deltaTime += (Time.deltaTime - deltaTime) * 0.1f;


     if (Input.GetKey(KeyCode.Escape))
     {
         Application.LoadLevel("Menu");
     }

     grounded = Physics2D.OverlapCircle(groundCheck.position, groundCheckRadius, whatIsGrounded);

     if (transform.position.x > speedMilestoneCount)
     {
         speedMilestoneCount += speedIncreaseMilestone;

         speedIncreaseMilestone = speedIncreaseMilestone * speedMutiplayer;

         moveSpeed = moveSpeed * speedMutiplayer;
     }

     myRigibody.velocity = new Vector2(moveSpeed, myRigibody.velocity.y);

     if (Input.GetKeyDown(KeyCode.Space) || Input.GetMouseButtonDown(0))
     {
         if (grounded)
         {
             myRigibody.velocity = new Vector2(myRigibody.velocity.x, jumpForce);
             stoppedJumping = false;
         }

         if (!grounded && canDoubleJump)
         {
             myRigibody.velocity = new Vector2(myRigibody.velocity.x, jumpForce);
             jumpTimeCounter = jumpTime;
             stoppedJumping = false;
             canDoubleJump = false;
         }
     }

     if ((Input.GetKey(KeyCode.Space) || Input.GetMouseButton(0)) && !stoppedJumping)
     {
         if (jumpTimeCounter > 0)
         {
             myRigibody.velocity = new Vector2(myRigibody.velocity.x, jumpForce);
             jumpTime -= Time.deltaTime;
         }
     }

     if (Input.GetKeyUp(KeyCode.Space) || Input.GetMouseButtonUp(0))
     {
         jumpTimeCounter = 0;
         stoppedJumping = true;
     }

     if (grounded)
     {
         jumpTimeCounter = jumpTime;
         stoppedJumping = true;
         canDoubleJump = true;
     }

     if (!grounded)
     {
         jumpTime = 0;
     }


     myAnimator.SetFloat("Speed", myRigibody.velocity.x);
     myAnimator.SetBool("Grounded", grounded);
 }

}