no idea what is wrong

it stands still with the if structure _onClicked. if i remove that it follows my mouse thats what i want but only if i hold my mousebutton if i release it it should go back.

using UnityEngine; using System.Collections;

public class gameman : MonoBehaviour {

 public GameObject ball;
 private GameObject currentball;
 public GameObject rekker;
 private bool loaded = true;

 private bool _onClicked = false;
 private Vector3 _Startpos;
 private Vector3 screenPoint;
 

 //private Vector3 newPosition;
 void Start()
 {
     _Startpos = rekker.transform.position;
 }

 // Update is called once per frame
 void Update()
 {
     if (loaded)
     {
         currentball = Instantiate(ball);
         currentball.transform.parent = rekker.transform;
         currentball.transform.localPosition = Vector3.zero;
         loaded = false;
     }
     if (_onClicked)
     {
         screenPoint = Camera.main.WorldToScreenPoint(gameObject.transform.position);
       
         Vector3 curScreenPoint = new Vector3(Input.mousePosition.x, Input.mousePosition.y, Input.mousePosition.z + 5);

         Vector3 curPosition = Camera.main.ScreenToWorldPoint(curScreenPoint);
         rekker.transform.position = curPosition;
     }
 }

 void OnMouseDown()
 {
    
     
     _onClicked = true;
     Debug.Log("tru");

 }

 void OnMouseUp()
 {
     
     _onClicked = false;
     rekker.transform.position = _Startpos;
     Debug.Log("false");
 }

}