Error unexpected symbol 'internal' What is wrong with this?

 public class BatteryCollect : MonoBehaviour {
 
     public int charge = 0;
     
     public Texture2D charge1tex;
     public Texture2D charge2tex;
     public Texture2D charge3tex;
     public Texture2D charge4tex;
     public Texture2D charge0tex;
     
     // initialise GUI texture to false (don't display it)
     void Start(){
         
         guiTexture.enabled = false;
         charge = 0;
         
     }
 
     //update function checks status of charge variable
     //which is increased via an external script 
     //each time the player collides (collects) with a battery
 
     void Update () {
 
       //first battery collected
       //assign the first texture image to guiTexture
       //and enable (display) texture
     
         if(charge == 1){
             
             guiTexture.texture = charge1tex;
             guiTexture.enabled = true;
             
         }
         
         // display subsequent textures to indicate power collected
         
         else if(charge == 2){
             
             guiTexture.texture = charge2tex;
         }
         
         else if(charge == 3){
             
             guiTexture.texture = charge3tex;
         }
         
         else if(charge == 4){
             
             guiTexture.texture = charge4tex;
         }
         
         else if(charge == 0){
             
             guiTexture.texture = charge0tex;
         }
 
     }
 
         public void setCharge(){
    
            
             // updates the charge variable via a message
    
             // from the PlayerCollions script
 
             charge = charge + 1 ;
         }    
 }