XNa Problem

I wanted to make a game for a pet care for windows phone 7 but Im having problem whit this it tell me that I have a null method but I don't know why I have a enum From each State in the game.


This is the main File.

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Input.Touch;
using Microsoft.Xna.Framework.Media;
using Mochi_Mochi_Pets_Life.Script.Screen;

namespace Mochi_Mochi_Pets_Life
{

public class MainFile : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
ScreenStates screentState;

Rectangle TouchS_Y_X;

Logo logo;
Menu0 menu;
Choose_Pets choose_pets;
ScreenStates.CurrentGameState GameState;

public MainFile()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
Content.RootDirectory = "Script\Screen";

choose_pets = new Choose_Pets();

this.screentState = new ScreenStates();
this.logo = new Logo(GraphicsDevice);
this.menu = new Menu0();
// Frame rate is 30 fps by default for Windows Phone.
TargetElapsedTime = TimeSpan.FromTicks(333333);

// Extend battery life under lock.
InactiveSleepTime = TimeSpan.FromSeconds(1);

GameState = ScreenStates.CurrentGameState.Logo;


}


protected override void Initialize()
{
choose_pets.Initialize_choosepets();
// TODO: Add your initialization logic here
base.Initialize();
}


protected override void LoadContent()
{
TouchS_Y_X = new Rectangle(0, 0, 1, 1);
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);

if (GameState == ScreenStates.CurrentGameState.Logo)
this.logo.Load(this.Content, this.GraphicsDevice);

if (GameState == ScreenStates.CurrentGameState.Menu)
this.menu.Load_Menu(GraphicsDevice, Content);

if (logo.FadeOut_logo == true)
GameState = ScreenStates.CurrentGameState.Menu;

if (GameState == ScreenStates.CurrentGameState.CharactersChooser)
this.choose_pets.Load_ChoosePet(this.Content, this.GraphicsDevice);
// TODO: use this.Content to load your game content here
}


protected override void UnloadContent()
{
// TODO: Unload any non ContentManager content here
//this.logo.Unload_logo(Content);
}


protected override void Update(GameTime gameTime)
{

// Allows the game to exit
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();

if (GameState == ScreenStates.CurrentGameState.Logo)
logo.Update_logo(gameTime);


if (GameState == ScreenStates.CurrentGameState.CharactersChooser)
choose_pets.Update_petchoose(gameTime);

// TODO: Add your update logic here

base.Update(gameTime);
}


protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.Black);

spriteBatch.Begin();

if (GameState == ScreenStates.CurrentGameState.Logo)
logo.Draw(spriteBatch);

if (logo.FadeOut_logo == true)
menu.Draw_Menu(spriteBatch);

if (GameState == ScreenStates.CurrentGameState.CharactersChooser)
choose_pets.Draw_petChoose(spriteBatch);

spriteBatch.End();
base.Draw(gameTime);
}
}
}

And This one is the Menu that is giving me the problems

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content;

namespace Mochi_Mochi_Pets_Life
{
class Menu0
{
Texture2D Text2D_Background;
Rectangle Rec_Background;

Texture2D ButtonText2DPlay;
Rectangle ButtonRecPlay;


public void Load_Menu(GraphicsDevice Graphics_Menu, ContentManager Content_Menu)
{
Content_Menu.RootDirectory = "Content";

Text2D_Background = Content_Menu.Load<Texture2D>("UI\MenuBack");
Rec_Background = new Rectangle(0, 0, Graphics_Menu.Viewport.Width, Graphics_Menu.Viewport.Height);

ButtonText2DPlay = Content_Menu.Load<Texture2D>("UI\Buttons\New Games");
ButtonRecPlay = new Rectangle(Graphics_Menu.Viewport.Width, 400, 150, 40);
}


public void Draw_Menu(SpriteBatch Spritebatch_Menu)
{
Spritebatch_Menu.Draw(Text2D_Background, Rec_Background, Color.White);
Spritebatch_Menu.Draw(ButtonText2DPlay, ButtonRecPlay, Color.White);
}
}
}

Ok what this does is that when my logo Fade is == true the Game State Jump to Main Manu but it never happen always error I will appreciate your help..