How Can i add a delay to my shoot script ?

Hi all i just made a shooting script and it works perfectly :) but the problem is the shooting is to fast i want a delay in there so if i press F on the keyboard rapidly it wont let me shoot until the delay time is over. I want to set the delay time as 1.5 sec and then the you can shoot again. After 1.5 sec you can shoot :) when you press F on the keyboard

Here is my script:

         var Range : float;
         
                 var Force : float = 1000;
 
                     var Clips : float = 100;
                     
                         var BulletsPerClip : float = 1;
                         
                         var ReloadTime: float = 0.6;
                         
                         
  var BulletsLeft : float = 0;
 
  
  var Delay : float = 2;
 var fireRate = 0.05;
 
 public var ShootSound : AudioClip;
 public var ReloadSound : AudioClip;
 function Update () {
 
         if(Input.GetKeyDown(KeyCode.F) && BulletsLeft ){
 
          PlayShootSound();
           ShootRay();
            
             
 
 }
 
 }
 
 function Start(){
 
 
    BulletsLeft = BulletsPerClip;
 
 
 
 }
 
 
 
 
 function ShootRay(){
 
   GameObject.Find("m1911pistoleReloadandShooting").animation.Play("Shoot") ;
     var hit: RaycastHit;
     
     var direction = transform.TransformDirection(Vector3.forward);
     
     Debug.DrawRay(transform.position, direction * Range, Color.yellow);
             
     if(Physics.Raycast( transform.position, direction, hit, Range)){
     
         if(hit.rigidbody){
         
     
          hit.rigidbody.AddForceAtPosition( Force * direction , hit.point);
        
     }
     }
 
 BulletsLeft--;
 
 if( BulletsLeft < 0){
   
      BulletsLeft = 0;
  }    
 
 if( BulletsLeft == 0){
  
  Reload();
 
 }
 }
 
 
 function Reload (){
 
 PlayReloadSound();
 GameObject.Find("m1911pistoleReloadandShooting").animation.Play("Reload") ;
  yield WaitForSeconds( ReloadTime);
    
    if( Clips >0){
  
   Clips -=1;
   BulletsLeft = BulletsPerClip; 
   
  }
 }
 
     function PlayShootSound()
     {
         audio.PlayOneShot(ShootSound);
     }
 
 function PlayReloadSound()
     {
         audio.PlayOneShot(ReloadSound);
     }

Please someone help me thank you so much :) MCHALO