Multiplayer Password

I am using a simple multiplayer script for javascript and I would like to add password protection and chat to it. Could someone please show me how to do this. I looked on docs.unity3d.com but I couldn't decipher it. I would like a gui password box to enter the password into. Here is the code:

 #pragma strict
 
 private var gameName : String = "New Game"; 
 private var roomName : String = "Example game";
 var versionNo : String = "V1.0";
 
 private var refreshing : boolean;
 private var hostData : HostData[];
 private var    outputText : String = "";
 private var    userName : String;
 
 private var btnX : float;
 private var btnY : float;
 private var btnW : float;
 private var btnH : float;
 
 function Start()
 {
     btnX = Screen.width * 0.05;
     btnY = Screen.width * 0.05;
     btnW = Screen.width * 0.1;
     btnH = Screen.width * 0.1;
     userName = PlayerPrefs.GetString("Username");
 }
 
 function startServer()
 {
     Network.InitializeServer(32, 25001, !Network.HavePublicAddress);
     MasterServer.RegisterHost(gameName, roomName, versionNo);
 }
 
 function refreshHostList()
 {
     MasterServer.RequestHostList(gameName);
     refreshing = true;
 }
 
 function Update()
 {
     if (refreshing)
     {
         if (MasterServer.PollHostList().Length > 0)
         refreshing = false;
         Debug.Log(MasterServer.PollHostList().Length);
         hostData = MasterServer.PollHostList();
     }
 }
 
 //Messages
 function OnServerInitialized()
 {
     Debug.Log("Server initialized");
     yield WaitForSeconds(0.5);
     Debug.Log("Room name is " + gameName);
     yield WaitForSeconds(1.5);
     Debug.Log("Player name is " + userName);
 }
 
 function OnConnectedToServer (){
     Debug.Log("Player name is " + userName);
 }
 
 function OnMasterServerEvent(mse : MasterServerEvent)
 {
     if(mse == MasterServerEvent.RegistrationSucceeded)
     {
         Debug.Log("Registered Server!");    
     }
 }
 
 //GUI
 function OnGUI()
 {
     if (!Network.isServer && !Network.isClient)
     {
     
         if (GUI.Button(Rect(Screen.width / 32, Screen.height / 16, 200,25), "Start Server"))
         {
             Debug.Log("Starting Server");
             startServer();
         }
         
         gameName = GUI.TextField(Rect(Screen.width / 32, Screen.height / 16 + 30, 100, 25), gameName);
         
         if (GUI.Button(Rect(Screen.width / 32, btnY * 1.4 + btnH, 200, 25), "Refresh Hosts"))
         {
             Debug.Log("Refreshing");
             refreshHostList();
         }
         
         if (hostData)
         {
             for (var i:int = 0; i < hostData.Length; i++)
             {
                 if (GUI.Button(Rect(Screen.width / 32 * 1.5 + btnW, Screen.height / 16 + (btnH * i),btnW * 3, btnH * 0.5), hostData[i].gameName))
                 {
                     Network.Connect(hostData[i]);
                 }
             }
         }
     }
 }
 
 //Chat portion