Problem with my project Vending machine C# WPF

Question

i cant seem to compare the result of the instered coins and the price of the drink
The Flow of the project.

 
1.The Report "Choose" shown on the screen on start window.
2.User chooses Drink /Coke/Water/Coffie/Beer//
 The choice is made by clicking on of the drinks in Make a Choice
 The drink and price displays next to the "current choice".
 The Report changes from choose to Pay.
3.The user can now click on the Coin Buttons  //2/1/0.50/0.20/0.10/0.05Euro//
 the total of the coin insert is displays next to the inserted coin(s)
4.When there is enough money inserted the coin buttons become inactive.
 and the button Buy drink becomes active
 the Report changes to buy drink
5.Afther the user clicks Buy drink
 The report changes to "take drink"
 below report there is another report given:
 -Take your "chosen drink"
 -money back "the money that is more than the price of the drink"
 -the total coin given back
 The button Take Drink becomes visble
 And all the rest of the buttons become inactive

 
6.After the user clicks on take drink the program starts again.
 
Note: Till point 4, the user can still change drink.So the If the drinks changes price and the inserted coins are blow or more than the chosen drink
 The Report changes also Pay or Buy
Prices are Coke 0,50€ /Water0,60€ /Coffie 1,20 / Beer 4€

 
pic: http://img338.imageshack.us/img338/5613/softdrinkvend.jpg
Code atm:
using System;

 
using System.Collections.Generic;

 
using System.Linq;

 
using System.Text;

 
using System.Windows;

 
using System.Windows.Controls;

 
using System.Windows.Data;

 
using System.Windows.Documents;

 
using System.Windows.Input;

 
using System.Windows.Media;

 
using System.Windows.Media.Imaging;

 
using System.Windows.Navigation;

 
using System.Windows.Shapes;

 
namespace Vending_Machine

 
{

 
/// <summary>

 
/// Interaction logic for Window1.xaml

 
/// </summary>

 
public partial class Window1 : Window

 
{

 


 
double result;

 


 
 

 
public Window1()

 
{

 
InitializeComponent();

 
}

 
 

 
 

 
private void btnCola_Click(object sender, RoutedEventArgs e)

 
{

 
Drank d;

 
d = new Drank();

 
double cola = d.coladrank();

 
lblSortDrink.Content = cola;

 
groupBox2.IsEnabled = true;

 


 
}

 
private void btnWater_Click(object sender, RoutedEventArgs e)

 
{

 
Drank d;

 
d = new Drank();

 
double water = d.waterdrank();

 
lblSortDrink.Content = water;

 


 
}

 
private void btnCoffie_Click(object sender, RoutedEventArgs e)

 
{

 
Drank d;

 
d = new Drank();

 
double koffie = d.koffiedrank();

 
lblSortDrink.Content = koffie;

 
groupBox2.IsEnabled = true;

 
}

 
private void btnBeer_Click(object sender, RoutedEventArgs e)

 
{

 
Drank d;

 
d = new Drank();

 
double soep = d.soepdrank();

 
lblSortDrink.Content = soep;

 
groupBox2.IsEnabled = true;

 
}

 
private void button11_Click(object sender, RoutedEventArgs e)

 
{

 


 
groupBox1.IsEnabled = false;

 
groupBox2.IsEnabled = false;

 
 

 
}

 
private void Window_Loaded(object sender, RoutedEventArgs e)

 
{

 
groupBox2.IsEnabled = false;

 
}

 
private void btnTwo_Click(object sender, RoutedEventArgs e)

 
{

 
Geld g;

 
g = new Geld();

 
double tweeEuro = g.tweeEurogeld();

 


 


 
if (Convert.ToDouble(lblSortDrink.Content) > (Convert.ToDouble((lblInsertedCoins.Content))))

 
{

 
result += tweeEuro;

 
lblInsertedCoins.Content = result;

 


 


 
}

 


 


 
}

 
 

 
private void btnOne_Click(object sender, RoutedEventArgs e)

 
{

 
Geld d;

 
d = new Geld();

 
double eenEuro = d.eenEurogeld();

 


 
if (Convert.ToDouble(lblSortDrink.Content) > (Convert.ToDouble((lblInsertedCoins.Content))))

 
{

 
result += eenEuro;

 
lblInsertedCoins.Content = result;

 
 

 
 

 
 

 
}

 


 
 

 
 

 
}

 
private void btnFifty_Click(object sender, RoutedEventArgs e)

 
{

 
Geld g;

 
g = new Geld();

 
double vijtigCent = g.vijtigCentgeld();

 


 
 

 
if (Convert.ToDouble(lblSortDrink.Content) > (Convert.ToDouble((lblInsertedCoins.Content))))

 
{

 
result += vijtigCent;

 
lblInsertedCoins.Content = result;

 
 

 
 

 
 

 
}

 


 
 

 
}

 
private void btnTwinty_Click(object sender, RoutedEventArgs e)

 


 
{

 
Geld g;

 
g = new Geld();

 
double twintigCent = g.twintigCentgeld();

 


 
if (Convert.ToDouble(lblSortDrink.Content) > (Convert.ToDouble((lblInsertedCoins.Content))))

 
{

 
result += twintigCent;

 
lblInsertedCoins.Content = result;

 
 

 
 

 
 

 
}

 


 


 


 
}

 
 

 
 

 
private void btnTen_Click(object sender, RoutedEventArgs e)

 
{

 
Geld g;

 
g = new Geld();

 
double tienCent = g.tienCentgeld();

 


 
if (Convert.ToDouble(lblSortDrink.Content) > (Convert.ToDouble((lblInsertedCoins.Content))))

 
{

 
result += tienCent;

 
lblInsertedCoins.Content = result;

 
 

 
 

 
 

 
}

 


 
}

 
private void BtnFive_Click(object sender, RoutedEventArgs e)

 
{

 
Geld g;

 
g = new Geld();

 
double vijfCent = g.vijfCentgeld();

 


 
if (Convert.ToDouble(lblSortDrink.Content) > (Convert.ToDouble((lblInsertedCoins.Content))))

 
{

 
result += vijfCent;

 
lblInsertedCoins.Content = result;

 
 

 
 

 
 

 
}

 


 
 

 
 

 
 

 
 

 
}

 
private void btnCancel_Click(object sender, RoutedEventArgs e)

 
{

 
groupBox2.IsEnabled = false;

 
btnBuy.IsEnabled = false;

 


 
}

 
private void btnBuy_Click(object sender, RoutedEventArgs e)

 
{

 
/*double priceDrink;

 
double insertedCoin;

 
double moneyback;

 
moneyback = priceDrink - insertedCoin;*/

 
}

 


 
 

 
 

 
}

 
}

 
 

 
and i made two classes

 
(Drinks)

 
using System;

 
using System.Collections.Generic;

 
using System.Linq;

 
using System.Text;

 
namespace Vending_Machine

 
{

 
partial class Drank

 
{

 
public int cola;

 
public int water;

 
public int koffie;

 
public int soep;

 
public double coladrank()

 
{

 
double cola = 1.00;

 
return cola;

 


 
}

 
public double waterdrank()

 
{

 
double water = 1.20;

 
return water;

 


 
}

 
public double koffiedrank()

 
{

 
double koffie = 2.50;

 
return koffie;

 
}

 
public double soepdrank()

 
{

 
double soep = 4.00;

 
return soep;

 
}

 


 
}

 
}

 
(money)

 
 

 
using System;

 
using System.Collections.Generic;

 
using System.Linq;

 
using System.Text;

 
namespace Vending_Machine

 
{

 


 
partial class Geld

 
{

 
public int tweeEuro;

 
public int eenEuro;

 
public int vijtigCent;

 
public int twintigCent;

 
public int tienCent;

 
public int vijfCent;

 
 

 
public double tweeEurogeld()

 
{

 
double tweeEuro = 2.00;

 
return tweeEuro;

 
}

 
public double eenEurogeld()

 
{

 
double eenEuro = 1.00;

 
return eenEuro;

 
}

 
public double vijtigCentgeld()

 
{

 
double vijtigCent = 0.50;

 
return vijtigCent;

 
}

 
public double twintigCentgeld()

 
{

 
double twintigCent = 0.20;

 
return twintigCent;

 
}

 
public double tienCentgeld()

 
{

 
double tienCent = 0.10;

 
return tienCent;

 
}

 
public double vijfCentgeld()

 
{

 
double vijfCent = 0.05;

 
return vijfCent;

 
}

 
}

 
}
 
any tips to resolving my noobie code^^