GUI not working in Build?

I have been struggling to work out the problem here.

I am toggling certain GUI elements depending on which buttons you press using booleans. Here is my script:

 @script ExecuteInEditMode()
 
 var gameName : String = "thetestgame123";
 
 var refreshing = false;
 var hostData : HostData[];
 
 var playerPrefab : GameObject;
 
 var create = false;
 var joining = false;
 
 var serverName = "";
 var serverPass = "";
 
 var clientPass = "";
  
 function OnGUI () {
 
     if(!Network.isClient && !Network.isServer) {
     
         if(!create && !joining){
     
             if (GUI.Button(Rect(Screen.width/2,Screen.height/2,100,20),"Create Game")) {
                 
                 create = true;
             }
     
              if (GUI.Button(Rect(Screen.width/2,Screen.height/2 + 30,100,20),"Find Game")) {
                 
                 joining = true;
                 refreshHostList();
             }
         }
         
         if (create){
             
             if (GUI.Button(Rect(Screen.width/2,Screen.height/2 + 60,100,20),"Create")) {
     
                 startServer();
             }
             
             GUI.Label(Rect (Screen.width/2 - 50,Screen.height/2,100,20),"Server Name:");
             GUI.Label(Rect (Screen.width/2 + 75,Screen.height/2,100,20),"Password:");
                 
             serverName = GUI.TextField (Rect (Screen.width/2 - 60,Screen.height/2 + 30,100,20), serverName, 25);
             serverPass = GUI.PasswordField (Rect (Screen.width/2 + 60,Screen.height/2 + 30,100,20), serverPass, "*"[0], 25);
             
             if (GUI.Button(Rect(Screen.width/1.2,Screen.height/20,100,20),"Back")) {
 
                    create = false;
             }
         }
         
         if (joining){
         
             if(hostData) {
     
                 for(var i:int = 0; i < hostData.length; i++) {
     
                     GUI.Label(Rect(Screen.width/2 - 50,Screen.height/2 + 60,100,20),hostData[i].gameName);
                     
                     clientPass = GUI.PasswordField (Rect (Screen.width/2 + 60,Screen.height/2 + 30,100,20), clientPass, "*"[0], 25);
             
                     if (GUI.Button(Rect(Screen.width/2,Screen.height/2 + 60,100,20),"Join")) {
     
                         Network.Connect(hostData[i]);
                     }
                 }
             }
             
             if (GUI.Button(Rect(Screen.width/1.2,Screen.height/20,100,20),"Back")) {
 
                    joining = false;
             }
             
             if(!hostData) {
             
                 joining = false;
             }
         }
         
         if (GUI.Button(Rect(Screen.width/20,Screen.height/20,100,20),"Quit")) {
 
                Application.Quit();
         }
     }
 }
 
 function Update () {
 
     if(refreshing) {
 
         if(MasterServer.PollHostList().Length > 0) {
 
             refreshing = false;
             hostData = MasterServer.PollHostList();
         }
     }
 }
 
 function startServer () {
     
     Network.incomingPassword = serverPass;
     Network.InitializeServer(32,25001, !Network.HavePublicAddress);
     MasterServer.RegisterHost(gameName, serverName, "this is a tutorial");
 }
 
 function OnServerInitialized () {
     
     DontDestroyOnLoad (transform.gameObject);
     
     Application.LoadLevel ("Lobby");
     
     lobbySpawn();
 }
 
 function OnConnectedToServer () {
 
     lobbySpawn();
 }
 
 function lobbySpawn(){
 
     yield WaitForSeconds(0.1);
 
     Network.Instantiate(playerPrefab, transform.position, transform.rotation, 0);
 }
 
 function refreshHostList () {
 
     MasterServer.RequestHostList(gameName);
     refreshing = true;
 }

The problem lies within the first section of the GUI function, where you press the create game button, the variable is changed to true, which means the button should stop being shown. The second set of 'creating' elements should now be visible.

This only works in the Unity Editor seen here:

However, is doesn't work in the Build seen here:

I have changed the variables around, added a function to delay the change in boolean a little, I have even tried moving the create and join buttons to a different script which destroys itself and created the shown script. All tests came back with exactly the same results. There are no errors when in the Editor. It has no obvious reason as to why it shouldn't work.