How to drag / pick up objects with Mouse.

How to drag / pick up objects with Mouse.

Im looking how to be able to grab and swing, drag or what ever -ANYWHERE on the screen with the click and hold of the mouse button,

this script I have should be accurate but its not working THIS IS A 2D GAME JAVSCRIPT

Please help and post corrected script

Keep in mind= -It Must be able to be dragged anywhere on screen

-On mouse hold button down

-upon release just lets go of object

 var spring = 50.0;
  var damper = 5.0;
  var drag = 10.0;
  var angularDrag = 5.0;
 5. var distance = 0.2;
  var attachToCenterOfMass = false;
  
  private var springJoint : SpringJoint;
  
 10. function Update ()
  {
      // Make sure the user pressed the mouse down
      if (!Input.GetMouseButtonDown (0))
          return;
 15. 
      var mainCamera = FindCamera();
          
      // We need to actually hit an object
      var hit : RaycastHit;
 20.     if (!Physics.Raycast(mainCamera.ScreenPointToRay(Input.mousePosition),  hit, 100))
          return;
      // We need to hit a rigidbody that is not kinematic
      if (!hit.rigidbody2D || hit.rigidbody2D.isKinematic)
          return;
 25.     
      if (!springJoint)
      {
          var go = new GameObject("Rigidbody dragger");
          var body : Rigidbody2D = go.AddComponent ("Rigidbody2D") as Rigidbody2D;
 30.         springJoint = go.AddComponent ("SpringJoint");
          body.isKinematic = true;
      }
      
      springJoint.transform.position = hit.point;
 35.     if (attachToCenterOfMass)
      {
          var anchor = transform.TransformDirection(hit.rigidbody.centerOfMass) + hit.rigidbody2D.transform.position;
          anchor = springJoint.transform.InverseTransformPoint(anchor);
          springJoint.anchor = anchor;
 40.     }
      else
      {
          springJoint.anchor = Vector3.zero;
      }
 45.     
      springJoint.spring = spring;
      springJoint.damper = damper;
      springJoint.maxDistance = distance;
      springJoint.connectedBody = hit.rigidbody;
 50.     
      StartCoroutine ("DragObject", hit.distance);
  }
  
  function DragObject (distance : float)
 55. {
      var oldDrag = springJoint.connectedBody.drag;
      var oldAngularDrag = springJoint.connectedBody.angularDrag;
      springJoint.connectedBody.drag = drag;
      springJoint.connectedBody.angularDrag = angularDrag;
 60.     var mainCamera = FindCamera();
      while (Input.GetMouseButton (0))
      {
          var ray = mainCamera.ScreenPointToRay (Input.mousePosition);
          springJoint.transform.position = ray.GetPoint(distance);
 65.         yield;
      }
      if (springJoint.connectedBody)
      {
          springJoint.connectedBody.drag = oldDrag;
 70.         springJoint.connectedBody.angularDrag = oldAngularDrag;
          springJoint.connectedBody = null;
      }
  }
  
 75. function FindCamera ()
  {
      if (GetComponent.<Camera>())
          return GetComponent.<Camera>();
      else
 80.         return Camera.main;
  }