Need help with making a character jump.

So, I've started on my own character movement script and can't seem to make my character jump without continuously flying if I continue to hold space down. I've looked around online for a solution and found a few jumping tutorials but they're not making very realistic jumps, can someone help me fix this? Here's my code so far (I've removed all the script I had for jumping)

 var rotationSpeed: float = 10;
 var walkSpeed : float = 3;
 var gravity : float = 50;
 private var yRot : float;
 
 function Update () 
 {
     var Controller : CharacterController = GetComponent(CharacterController);
     var vertical : Vector3 = transform.TransformDirection(Vector3.forward);
     var horizontal : Vector3 = transform.TransformDirection(Vector3.right);
     var height : Vector3 = transform.TransformDirection(Vector3.up);    
     
     if(Input.GetAxis("Vertical")||Input.GetAxis("Horizontal"))
     {
         animation.CrossFade("Default Walk",0.2);
         Controller.Move((vertical * (walkSpeed * Input.GetAxis("Vertical"))) * Time.deltaTime);
         Controller.Move((horizontal * (walkSpeed * Input.GetAxis("Horizontal"))) * Time.deltaTime);
     }
             else
         {
             animation.CrossFade("Default Idle",0.2);
         }
     
     if(Input.GetAxis("Mouse X"))
     {
         yRot += 10* Input.GetAxis("Mouse X");        
     }
     transform.rotation = Quaternion.Euler(0,yRot,0);
     
     Controller.Move(height * gravity * Time.deltaTime);
 }