Tutorial Script: Menumanager

using UnityEngine;
using System.Collections;

public class MenuManager : MonoBehaviour
{
    public MenuManager instance;

    public string CurrentMenu;

    public string MatchName = "";
    public string MatchPassword = "";
    public int MatchMaxPlayers = 32;

    private Vector2 ScrollLobby = Vector2.zero;
    private string iptemp = "127.0.0.1";

    void Start()
    {
        instance = this;
        CurrentMenu = "Main";
        MatchName = "HeyHeyWelcome " + Random.Range(0, 5000);
    }

    void FixedUpdate()
    {
        instance = this;
    }

    void OnGUI()
    {
        if (CurrentMenu == "Main")
            Menu_Main();
        if (CurrentMenu == "Lobby")
            Menu_Lobby();
        if (CurrentMenu == "Host")
            Menu_HostGame();
        if (CurrentMenu == "ChoMap")
            Menu_ChooseMap();
    }

    public void NavigateTo(string nextmenu)
    {
        CurrentMenu = nextmenu;
    }

    private void Menu_Main()
    {
        if (GUI.Button(new Rect(10, 10, 200, 50), "Host Game"))
        {
            NavigateTo("Host");
        }
        if (GUI.Button(new Rect(10, 70, 200, 50), "Refresh"))
        {
            MasterServer.RequestHostList("DeathMatch");
        }

        GUI.Label(new Rect(220, 10, 130, 30), "Player Name");
        MultiplayerManager.instance.PlayerName = GUI.TextField(new Rect(350, 10, 150, 30), MultiplayerManager.instance.PlayerName);
        if (GUI.Button(new Rect(510, 10, 100, 30), "Save Name"))
        {
            PlayerPrefs.SetString("PlayerName", MultiplayerManager.instance.PlayerName);
        }

        GUI.Label(new Rect(220, 50, 130, 30), "Direct Connect");
        iptemp = GUI.TextField(new Rect(350, 50, 150, 30), iptemp);
        if (GUI.Button(new Rect(510, 50, 100, 30), "Connect"))
        {
            Network.Connect(iptemp, 2550);
        }

        GUILayout.BeginArea(new Rect(Screen.width - 400, 0, 400, Screen.height), "Server List", "Box");
        GUILayout.Space(20);
        foreach (HostData match in MasterServer.PollHostList())
        {
            GUILayout.BeginHorizontal("Box");

            GUILayout.Label(match.gameName);
            if (GUILayout.Button("Connect"))
            {
                Network.Connect(match);
            }

            GUILayout.EndHorizontal();
        }

        GUILayout.EndArea();
    }

    private void Menu_HostGame()
    {
        //Buttons Host Game
        if (GUI.Button(new Rect(10, 10, 200, 50), "Back"))
        {
            NavigateTo("Main");
        }

        if (GUI.Button(new Rect(10, 60, 200, 50), "Start Server"))
        {
            MultiplayerManager.instance.StartServer(MatchName, MatchPassword, MatchMaxPlayers);
        }

        if (GUI.Button(new Rect(10, 160, 200, 50), "Choose Map"))
        {
            NavigateTo("ChoMap");
        }

        GUI.Label(new Rect(220, 10, 130, 30), "Match Name");
        MatchName = GUI.TextField(new Rect(400, 10, 200, 30), MatchName);

        GUI.Label(new Rect(220, 50, 130, 30), "Match Password");
        MatchPassword = GUI.PasswordField(new Rect(400, 50, 200, 30), MatchPassword, '*');

        GUI.Label(new Rect(220, 90, 130, 30), "Match Max Players");
        GUI.Label(new Rect(400, 90, 200, 30), (MatchMaxPlayers + 1).ToString());
        MatchMaxPlayers = Mathf.Clamp(MatchMaxPlayers, 8, 31);

        if (GUI.Button(new Rect(425, 90, 30, 20), "+"))
            MatchMaxPlayers += 2;
        if (GUI.Button(new Rect(455, 90, 30, 20), "-"))
            MatchMaxPlayers -= 2;

        GUI.Label(new Rect(650, 10, 130, 30), MultiplayerManager.instance.CurrentMap.MapName);
    }

    private void Menu_Lobby()
    {
        ScrollLobby = GUILayout.BeginScrollView(ScrollLobby, GUILayout.MaxWidth(200));

        foreach (MPPlayer pl in MultiplayerManager.instance.PlayerList)
        {
            if (pl.PlayerNetwork == Network.player)
                GUI.color = Color.blue;
            GUILayout.Box(pl.PlayerName);
            GUI.color = Color.white;
        }

        GUILayout.EndScrollView();

        GUI.Box(new Rect(250, 10, 200, 40), MultiplayerManager.instance.CurrentMap.MapName);

        if (Network.isServer)
        {
            if (GUI.Button(new Rect(Screen.width - 200, Screen.height - 80, 200, 40), "Start Match"))
            {
                MultiplayerManager.instance.networkView.RPC("Client_LoadMultiplayerMap", RPCMode.AllBuffered, MultiplayerManager.instance.CurrentMap.MapLoadName, MultiplayerManager.instance.oldprefix + 1);
                MultiplayerManager.instance.oldprefix += 1;
                MultiplayerManager.instance.IsMatchStarted = true;
            }
        }
        if (GUI.Button(new Rect(Screen.width - 200, Screen.height - 40, 200, 40), "Disconnect"))
        {
            Network.Disconnect();
        }
    }

    private void Menu_ChooseMap()
    {
        if (GUI.Button(new Rect(10, 10, 200, 50), "Back"))
        {
            NavigateTo("Host");
        }

        GUI.Label(new Rect(220, 10, 130, 30), "Choose Map");
        GUILayout.BeginArea(new Rect(350, 10, 150, Screen.height));

        foreach(MapSetting map in MultiplayerManager.instance.MapList)
        {
            if (GUILayout.Button(map.MapName))
            {
                NavigateTo("Host");
                MultiplayerManager.instance.CurrentMap = map;
            }
        }

        GUILayout.EndArea();
    }

    void OnServerInitialized()
    {
        NavigateTo("Lobby");
    }

    void OnConnectedToServer()
    {
        NavigateTo("Lobby");
    }

    void OnDisconnectedFromServer(NetworkDisconnection info)
    {
        NavigateTo("Main");
    }
}