Help with jump

I have a script and i am trying to get the cube to jump on a swipe up, can some one point me in the right direction, thanks

 function Update()
 {
         
     var tap = false;
     var swipeUp = false;
     var swipeDown = false;
     
     if(Input.touchCount > 0)
     
     {
         var touch = Input.GetTouch(0);
         if (touch.phase == TouchPhase.Began ||
         ((touch.phase == TouchPhase.Moved || touch.phase == TouchPhase.Stationary)
         && fingerDownTime <=0))
         
         
         {
             fingerDownTime = Time.time;
             fingerDownPos = touch.position;
         }
         
         else if (touch.phase == TouchPhase.Ended)
         
         {
             if((touch.position.y - fingerDownPos.y) > swipeThreshhold)
             swipeUp = true;
             
             else if((touch.position.y - fingerDownPos.y) < -swipeThreshhold)
             swipeDown=true;
     
         
             else
             tap = true;
             fingerDownTime = -1;
         }    
     }
 
 
     var horizontal = Input.GetAxis("Horizontal");
     horizontal += -Input.acceleration.y * accelerometerScale;
     trans.Rotate(0,rotateSpeed * horizontal * Time.deltaTime ,0);
     
     if (character.isGrounded && Input.GetKeyDown(KeyCode.Space) || tap)
     Pedal();
     
     
       var moveDirection = trans.forward * speed;
       moveDirection += Physics.gravity;
      character.Move(moveDirection * Time.deltaTime);  
     
     if(character.isGrounded)
   {
         if(speed < 0.3)
             speed = 0;
             else
             {
                 speed -= decayRate * Time.deltaTime * speed;
                }
  }
 }