Javascript Gun Firing Script Edit

Hello today I have made a gun script, it is working fine except that you can fire the gun everywhere even if you are not holding it. As you can imagine this is a problem. (DO NOT GIVE ME YOUR SCRIPT, JUST FIX THIS ONE)

Pick Up Script, may be useful for work but also might not

 var SpawnTo: Transform;
 var Gun : Transform;
 function OnTriggerEnter(hit:Collider)
 {
 if(hit.gameObject.tag == "Player")
 {
 Gun.parent = SpawnTo;
 Gun.transform.position = SpawnTo.transform.position;
 Gun.transform.rotation = SpawnTo.transform.rotation;
 }
 }

Gun Firing Script #pragma strict var Effect : Transform; var TheDammage = 30; var AudioShot : AudioClip;

 function OnTriggerEnter () {
     
     var hit : RaycastHit;
     var ray : Ray = Camera.main.ScreenPointToRay(Vector3(Screen.width*0.5, Screen.height*0.5, 0));
     
     if (Input.GetMouseButtonDown(0))
     audio.PlayOneShot(AudioShot,0.7);
     if (Input.GetMouseButtonDown(0))
     {
         if (Physics.Raycast (ray, hit, 100))
         {
             var particleClone = Instantiate(Effect, hit.point, Quaternion.LookRotation(hit.normal));
             Destroy(particleClone.gameObject, 2);
             hit.transform.SendMessage("ApplyDammage", TheDammage, SendMessageOptions.DontRequireReceiver);
         }
     }
     
 }