Error CS0103?

Hi,

I'm getting a CS0103 error, "The name "ballPosition" does not exist it the current context" on line 25, A.k.a: ballPostition = transform.position + new Vector3(0, 1f, 0);

Here is my code:

 using UnityEngine;
 using System.Collections;
 
 public class paddleScript : MonoBehaviour {
     
      float paddleSpeed = 10f;
      public GameObject ballPrefab;
     
     
      GameObject attachedBall = null;
     
     // Use this for initialization
     void Start () {
         
         
         
         
     SpawnBall();    
     
     }
     
     void SpawnBall() {
         //Spawns the ball, duh!
         
         ballPostition = transform.position + new Vector3(0, 1f, 0);
         Quaternion ballRotation = Quaternion.identity;    
         
         attachedBall = (GameObject)Instantiate( ballPrefab, ballPostition, ballRotation );
     }    
     
     // Update is called once per frame
     void Update () {
     
         transform.Translate ( paddleSpeed * Time.deltaTime * Input.GetAxis ( "Horizontal" ), 0, 0 );
         
         if( attachedball ) {
          attachedBall.rigidbody = transform.position + new Vector3(0, .75f, 0);    
         }    
         if( Input.GetButtonDown( "Jump" ) ){
            //Fire the ball!
            if( attachedball ) {
            attachedBall.rigidbody.isKinematic = false;        
            attachedBall.rigidbody.Addforce(0, 300f, 0);
            attachedBall = null;        
             
         }
     }
 }        
     
     
     void  OnCollisionEnter( Collision col ) {
         foreach (ContactPoint contact in col.contacts) {
         if( contact.thisCollider == collider ) {
                  float english = contact.point.x - transform.position.x;
                 
                 contact.otherCollider.rigidbody.AddForce( 300f * english, 0, 0);
             }
             
         }
     }    
 }