Picking up objects

This question is a bit too general, but I shall try to help.

Click on an Object to select it :

 private var imSelected : Transform;
 private var imClickedOn : boolean = false;

 // in function

     if (Input.Get$$anonymous$$ouseButtonDown(0)) 
     {   
        var rayHit : RaycastHit;
        if(Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), rayHit)) 
        {
          imSelected = rayHit.transform;
          if (imSelected == this.transform) {imClickedOn = true;}
        }
     }