Call JavaScript from c# Help!

Hi!

I have an inventory script and a pick up script. I'm using it for picking up batteries around my evel.

The problem I have is when I've picked up a battery and want to use it, it needs to call a function from a JavaScript file that I'm using for my flashlight. Do any of you guys know how to do that?

Note! I'm using this part of code in a JavaScript when I'm calling the flashlight function "Flashlight.AlterEnergy(batteryPower);"

Inventory script:

 using UnityEngine;
 using System.Collections;
 
 public class Inventory : MonoBehaviour {
     //GUI Skin
     public GUISkin InvSkin;
     //Slots
     public static string slot1 = "Empty 1";
     public static string slot2 = "Empty 2";
     public static string slot3 = "Empty 3";
     public static string currentItem = "None";
     //Other Vars
     private bool isenabled = false;
     private int messageint = 0;
     private string messagetext = "";
     private bool remove = false;
 
 
     void Update()
     {
        
             if (messageint >= 0)
             {
                 messageint--;
             }
 
         if (Input.GetKeyDown(KeyCode.Alpha1))
         {
             currentItem = slot1;
             messageint = 100;
             messagetext = slot1 + " Used";
             ActivateItems(currentItem);;
         }
         else if (Input.GetKeyDown(KeyCode.Alpha2))
         {
             currentItem = slot2;
             messageint = 100;
             messagetext = slot2 + " Used";
             ActivateItems(currentItem);
         }
         else if (Input.GetKeyDown(KeyCode.Alpha3))
         {
             currentItem = slot3;
             messageint = 100;
             messagetext = slot3 + " Used";
             ActivateItems(currentItem);
         }
         if (Input.GetKeyDown(KeyCode.Tab))
         {
             if (isenabled)
             {
                 isenabled = false;
             }
             else if (!isenabled)
             {
                 isenabled = true;
             }
         }
     }
 
     void OnGUI()
     {
         GUI.skin = InvSkin;
         if (messageint > 1)
         {
             GUI.Label(new Rect(Screen.width/2-50, Screen.height/2-55, 120, 50),messagetext);
         }
         if (isenabled)
         {
             if (GUI.Button(new Rect(Screen.width / 2 - 170, Screen.height / 2 + 390, 100, 30), slot1))
             {
                 if (!remove)
                 {
                     currentItem = slot1;
                     messageint = 100;
                     messagetext = slot1 + " Used";
                     ActivateItems(currentItem);
                     slot1 = "Empty 1";
                 }
                 else
                 {
                     messageint = 100;
                     messagetext = slot1 + " Removed";
                     slot1 = "Empty 1";
                     remove = false;
                 }
             }
             if (GUI.Button(new Rect(Screen.width / 2 - 40, Screen.height / 2 + 390, 100, 30), slot2))
             {
                 if (!remove)
                 {
                     currentItem = slot2;
                     messageint = 100;
                     messagetext = slot2 + " Used";
                     ActivateItems(currentItem);
                     slot2 = "Empty 2";
                 }
                 else
                 {
                     messageint = 100;
                     messagetext = slot2 + " Removed";
                     slot2 = "Empty 2";
                     remove = false;
                 }
             }
             if (GUI.Button(new Rect(Screen.width / 2 +90, Screen.height / 2 + 390, 100, 30), slot3))
             {
                 if (!remove)
                 {
                     currentItem = slot3;
                     messageint = 100;
                     messagetext = slot3 + " Used";
                     ActivateItems(currentItem);
                     slot3 = "Empty 3";
                 }
                 else
                 {
                     messageint = 100;
                     messagetext = slot3 + " Removed";
                     slot3 = "Empty 3";
                     remove = false;
                 }
             }
             if (remove)
             {
                 if (GUI.Button(new Rect(Screen.width / 2 + 300, Screen.height / 2 + 390, 100, 30), "Stop"))
                 {
                     remove = false;
                 }
             }
             else if (!remove)
             {
                 if (GUI.Button(new Rect(Screen.width / 2 + 300, Screen.height / 2 + 390, 100, 30), "Remove"))
                 {
                     remove = true;
                 }
             }
         }
     }
     void ActivateItems(string slot)
     {
        
     }
     
 }