unexpected symbol `:' in class, struct, or interface member declaration Pls Help

public class TouchControl : MonoBehaviour { private var dist : float; private var toDrag : Transform; private var dragging = false; private var offset : Vector3;

 function Update() {

     if(Input.GetMouseButtonDown(0))
     {
         var hit : RaycastHit;
         var v3 : Vector3;
         var ray : Ray = Camera.main.ScreenPointToRay(Input.mousePosition); 
         if(Physics.Raycast(ray,hit))
         {
             if(hit.transform.gameObject == selectedObject)
             {
                 toDrag = hit.transform;
                 dist = hit.transform.position.z - Camera.main.transform.position.z;
                 v3 = Vector3(Input.mousePosition.x, Input.mousePosition.y, dist);
                 v3 = Camera.main.ScreenToWorldPoint(v3);
                 offset = toDrag.position - v3;
                 dragging = true;
             }
         }
     }
     if (Input.GetMouseButton(0))
     {
         if (dragging)
         {
             v3 = Vector3(Input.mousePosition.x, Input.mousePosition.y, dist);
             v3 = Camera.main.ScreenToWorldPoint(v3);
             toDrag.position = v3 + offset;
         }
     }
     if (Input.GetMouseButtonUp(0))
     {
         dragging = false;
     }
 }

}

Hi guys im trying to set finger swipe drag with script but it gives error :( Im newbie in scripting so can anyone help me with this pls. Ty for ur interest