JS Main menu issues?

Hey Unity! I'm new to Java Script and I am trying to make a Main Menu. Its not working, and I have never seen this error before. Please help.

Thanks in advance!

Code:

 #pragma strict
 var skin:GUISkin;
 private var gldepth = -0.5;
 private var startTime = 0.1;
 var nativeVerticalResolution = 1200.0;
 var scaledResolutionWidth = nativeVerticalResolution / Screen.height * Screen.width;
 var mat:Material;
 private var tris = 0;
 private var verts = 0;
 private var savedTimeScale:float;
 private var pauseFilter;
 private var showfps:boolean;
 private var showtris:boolean;
 private var showvtx:boolean;
 private var showfpsgraph:boolean;
 var lowFPSColor = Color.red;
 var highFPSColor = Color.green;
 var lowFPS = 30;
 var highFPS = 50;
 //var start : GameObject;
 var url = "WebPlayer.html";
 var statColor:Color = Color.yellow;
 var GuiColor:Color = Color.white;
 
 var credits:String[]=[
 
     "Credits:",
 
     "armedunity.com",
 
     "bbb",
 
     "aaa"] ;
 var crediticons:Texture[];
 
 enum Page { None,Main,Options,Credits,Play }
 
 var currentPage:Page;
 private var fpsarray:int[];
 private var fps:float;
 
  
 function EndPage() {
 
     GUILayout.EndArea();
     if (currentPage != Page.Main) {
         ShowBackButton();
     }
 }
 function ShowBackButton() {
 
     if (GUI.Button(Rect(10,10,150,80),"Back")) {
         currentPage = Page.Main;
     }
 }
 function StatControl() {
 
     GUILayout.BeginHorizontal();
     showfps = GUILayout.Toggle(showfps,"FPS");
     showtris = GUILayout.Toggle(showtris,"Triangles");
     showvtx = GUILayout.Toggle(showvtx,"Vertices");
     showfpsgraph = GUILayout.Toggle(showfpsgraph,"FPS Graph");
     GUILayout.EndHorizontal();
 }
 function Qualities() {
 
     switch (QualitySettings.currentLevel) {
 
         case QualityLevel.Fastest:
 
         GUILayout.Label("Fastest");
 
         break;
 
         case QualityLevel.Fast:
 
         GUILayout.Label("Fast");
 
         break;
 
         case QualityLevel.Simple:
 
         GUILayout.Label("Simple");
 
         break;
 
         case QualityLevel.Good:
 
         GUILayout.Label("Good");
 
         break;
 
         case QualityLevel.Beautiful:
 
         GUILayout.Label("Beautiful");
 
         break;
 
         case QualityLevel.Fantastic:
 
         GUILayout.Label("Fantastic");
 
         break;
     }
 }
 function QualityControl() {
 
     GUILayout.BeginHorizontal();
 
     if (GUILayout.Button("Decrease")) {
         QualitySettings.DecreaseLevel();
     }
 
     if (GUILayout.Button("Increase")) {
         QualitySettings.IncreaseLevel();
     }
     GUILayout.EndHorizontal();
 }
 function BeginPage(width,height) {
     scaledResolutionWidth = nativeVerticalResolution / Screen.height * Screen.width;
     GUILayout.BeginArea(Rect(scaledResolutionWidth/2 - 2, nativeVerticalResolution/2 - 2,width,height));
 }
 function VolumeControl() {
 
     GUILayout.Label("Volume");
     AudioListener.volume = GUILayout.HorizontalSlider(AudioListener.volume,0.0,1.0);
 }
 
 private var toolbarInt:int=0;
 private var toolbarStrings: String[]= ["Audio","Graphics","Stats","System"];
 function ShowDevice() {
  
     GUILayout.Label ("Unity player version "+Application.unityVersion);
 
     GUILayout.Label("Graphics: "+SystemInfo.graphicsDeviceName+" "+
 
     SystemInfo.graphicsMemorySize+"MB    "+
 
     SystemInfo.graphicsDeviceVersion+"   "+
 
     SystemInfo.graphicsDeviceVendor);
 
     GUILayout.Label("Shadows: "+SystemInfo.supportsShadows);
 
     GUILayout.Label("Image Effects: "+SystemInfo.supportsImageEffects);
 
     GUILayout.Label("Render Textures: "+SystemInfo.supportsRenderTextures);
  
 
 }
 
 function Start () {
  switch (currentPage){
  case Page.Play: Play(); break;
 
     case Page.Options: ShowToolbar(); break;
 
     case Page.Credits: ShowCredits(); break;
  }
 }
  //pages
 
 function Play() {
  BeginPage(600,600);
  if(GUILayout.Button ("Campaign")) {
  Application.LoadLevel("start");
  }
  EndPage();
  }
  
 function ShowCredits() {
 
      BeginPage(600,600);
 
      for (var credit in credits) {
          GUILayout.Label(credit);
      }
 
      for (var credit in crediticons) {
          GUILayout.Label(credit);
      }
 
      EndPage();
  }
 function ShowToolbar() {
 
     BeginPage(800,250);
     toolbarInt = GUILayout.Toolbar (toolbarInt, toolbarStrings);
 
     switch (toolbarInt) {
 
         case 0: VolumeControl(); break;
 
         case 3: ShowDevice(); break;
 
         case 1: Qualities(); QualityControl(); break;
 
         case 2: StatControl(); break;
     }
     EndPage();
 }
  
 function update(){
  if (GUILayout.Button ("Play")) {
         currentPage = Page.Play;
     }
 
     if (GUILayout.Button ("Multiplayer")) {
         Application.LoadLevel("mp");
     }
 
     if (GUILayout.Button ("Zombies To be added.")) {
         //add zombies
     }
     if (GUILayout.Button ("Options")) {
         currentPage = Page.Options;
     }
     if (GUILayout.Button ("Credits")) {
         currentPage = Page.Credits;
     }
     if (GUILayout.Button ("Quit")) {
         Application.Quit();
     }
 }

Error: Assets/Scripts/mainmenu.js(36,6): BCE0132: The namespace '' already contains a definition for 'Page'.