move top down cmaera on left click code example

Example: unity drag camera

if(Input.GetMouseButtonDown(0))         {             bDragging = true;             oldPos = transform.position;             panOrigin = Camera.main.ScreenToViewportPoint(Input.mousePosition);                    //Get the ScreenVector the mouse clicked         }          if(Input.GetMouseButton(0))         {             Vector3 pos = Camera.main.ScreenToViewportPoint(Input.mousePosition) - panOrigin;    //Get the difference between where the mouse clicked and where it moved             transform.position = oldPos + -pos * panSpeed;                                         //Move the position of the camera to simulate a drag, speed * 10 for screen to worldspace conversion         }          if(Input.GetMouseButtonUp(0))         {             bDragging = false;         }