can anyone help me to smooth the jump?

hello guys i need a little help i have a player jump correctly when i'm not moving ..but when i'm running if i press the space bar and release it when my player is in air , i noticed that the player makes a double charged jump and i don't want that, i want to make single jump using UnityEngine; using System.Collections;

public class player_motion123 : MonoBehaviour {

 public Animator anim;
 //public Transform center_point;
 public Quaternion newrotation;
 public float smooth = 0.05f;


 public float speed;
 public CharacterController controller;
 public static bool ismoving=false;
 public static bool isRunning=false;

 public Transform cam;
 bool grounded;

 // jump


 private float verticalVelocity;
 public float gravity;
 public float JumpForce;
 public float JumpForce2;
 public bool jumping;







 void Start()
 {
     
 }




 void Update ()
 {
     
     float v = Input.GetAxis ("Vertical");

     float h = Input.GetAxis ("Horizontal");

     if (player_Sword_Attack.attacking == false) 
     {
         Move (h, v);
         Run (h, v);
         jump ();

     }



 }



 void Move(float h ,float v)

 {
     
     if (h != 0f || v != 0f)
     {
         
         rotate (v, h);
         controller.SimpleMove (transform.forward * speed);
         anim.SetFloat ("Speed", 0.5f);
         ismoving = true;
     } else {
         anim.SetFloat ("Speed",0);
         ismoving = false;
     }

 }


 void Run(float h, float v)
 {
     if (ismoving && Input.GetKey (KeyCode.LeftShift)) {

         rotate (v, h);
         controller.SimpleMove (transform.forward * speed * 2);
         anim.SetFloat ("Speed", 1);
         isRunning = true;
     }
     else if (ismoving && Input.GetKeyUp (KeyCode.LeftShift)) {
         anim.SetFloat ("Speed", 0.5f);
         isRunning = false;
     }
     else if (!ismoving && Input.GetKeyUp (KeyCode.LeftShift)) {
         anim.SetFloat ("Speed", 0);
         isRunning = false;
     }



 }




 void jump()
 {
     
     if (controller.isGrounded) 
     {
         verticalVelocity = -gravity * Time.deltaTime;
         anim.SetBool ("Jumping",false);
         if (Input.GetKeyDown (KeyCode.Space)) 
         {
             verticalVelocity = JumpForce;
             jumping = true;
             if (isRunning)
             verticalVelocity = JumpForce2;
             
             jumping = true;

         }
     }
     else 
     {
         
         verticalVelocity -= gravity * Time.deltaTime;
         if(Input.GetKeyUp(KeyCode.Space))
         anim.SetBool ("Jumping",true);
         jumping = false;

     }
     Vector3 moveVector = Vector3.zero;
     moveVector.x = Input.GetAxis ("Horizontal");
     moveVector.y = verticalVelocity;
     moveVector.z = Input.GetAxis("Vertical")*5.0f;
     controller.Move (moveVector*Time.deltaTime);




 }







 void rotate(float v,float h) {
     if (v > 0)
     {
         if (h > 0)
         {
             newrotation = Quaternion.Euler(0,cam.eulerAngles.y+45,0);
         }
         else if (h < 0)
         {
             newrotation = Quaternion.Euler(0,cam.eulerAngles.y+305,0);
         }
         else
         {
             newrotation = Quaternion.Euler(0,cam.eulerAngles.y,0);
         }
     }
     else if (v < 0)
     {
         if (h > 0)
         {
             newrotation = Quaternion.Euler(0,cam.eulerAngles.y+135,0);
         }
         else if (h < 0)
         {
             newrotation = Quaternion.Euler(0,cam.eulerAngles.y+225,0);
         }
         else {
             newrotation = Quaternion.Euler(0,cam.eulerAngles.y+180,0);
         }
     }
     else
     {
         if (h > 0)
         {
             newrotation = Quaternion.Euler(0,cam.eulerAngles.y+90,0);
         }
         else if (h < 0)
         {
             newrotation = Quaternion.Euler(0,cam.eulerAngles.y+270,0);
         }
         else {
             newrotation = transform.rotation;
         }
     }


     newrotation.x = 0;

     newrotation.z = 0;

     //We only want player to rotate in y axis
     transform.rotation = Quaternion.Slerp (transform.rotation,newrotation, smooth);

     //Slerp from player's current rotation to the new intended rotaion smoothly 
 }

}