need help converting gun script from c# to javascript

a user named BMayne answered my question here

he gave this script as a answer to show me a better way to do that kind of shooting

 float currentAmmo = 5.0f;
 float currentReloadTime = 0.0f;
 bool isReloading = false;
  
 const float RELOAD_TIME = 2.0f;
 const int MAX_AMMO = 8; 
  
  
 void Update()
 {
     if (Input.GetKeyDown(KeyCode.R))
     {
         if (currentAmmo != MAX_AMMO && !isReloading) // if we already have max ammo lets leave or if we are already reloading
         {
             isReloading = true; // We are now reloading
             currentReloadTime = RELOAD_TIME; //Set our current load time 
         }
     }
  
     if (isReloading)
         ReloadStep();
     else
         GunStep();
  
  
 }
  
 void GunStep()
 {
     if (currentAmmo <= 0)
         return; //No ammo so we leave.
  
     if (!Input.GetMouseButtonDown(0)) //the '!' means Not. so the mouse button is Not Down 
         return; //We are not firing so we don't need to be here
  
     //We fired our gun so we need to use a bullet 
     currentAmmo--;
  
     //Start our making our raycast
     RaycastHit hit;
     Ray ray = Camera.main.ScreenPointToRay(new Vector3((float)Screen.width * 0.5f, (float)Screen.height * 0.5f, 0.0f));
  
     //Fire the ray and tell anything we hit to apply damage
     if (Physics.Raycast(ray, out hit, 100))
     {
         hit.transform.SendMessage("ApplyDamage", TheDamage, SendMessageOptions.DontRequireReceiver);
     }
 }
  
 void ReloadStep()
 {
     currentReloadTime -= Time.deltaTime; //We count down
  
     if( currentReloadTime <= 0.0f )
     {
         isReloading = false;
         currentAmmo = MAX_AMMO;
     }
 }
 

and I use javascript so i was wondering if someone could convert this to javascript so i can understand it better. thanks in advance.