Changing Foreground color of labels, Depending on the current label mouseDown in MVVM

Hi all,

I have a simple WPF Applicaton in WPF. I have written all the UI code in code-behind. 

but I want to write this code in the ViewModel rather then writing in code-behind.

<Window x:Class="WpfMvvmApplication1.Views.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Window1" Height="300" Width="300"><Grid><Grid.RowDefinitions><RowDefinition Height="50" /><RowDefinition Height="*" /></Grid.RowDefinitions><StackPanel Grid.Row="0"  Orientation="Horizontal"><Label Foreground="Black" x:Name="lbl1" Content="Show Panel 1" MouseDown="Label_MouseDown" FontWeight="Bold"></Label><Label Foreground="Gray" x:Name="lbl2" Content="Show Panel 2" MouseDown="Label_MouseDown_1" FontWeight="Bold"></Label><Label Foreground="Gray" x:Name="lbl3" Content="Show Panel 3" MouseDown="Label_MouseDown_2" FontWeight="Bold"></Label></StackPanel><Grid Grid.Row="1"><StackPanel Visibility="Visible" Background="LemonChiffon" x:Name="panel1"><TextBlock Text="Panel 1 is on top" /></StackPanel><StackPanel Visibility="Collapsed"  Background="YellowGreen" x:Name="panel2"><TextBlock Text="Panel 2 is on top" /></StackPanel><StackPanel Visibility="Collapsed"  Background="WhiteSmoke" x:Name="panel3"><TextBlock Text="Panel 3 is on top" /></StackPanel></Grid></Grid></Window>

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.Shapes;

namespace WpfMvvmApplication1.Views
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }

        private void Label_MouseDown(object sender, MouseButtonEventArgs e)
        {
            lbl1.Foreground = Brushes.Black;
            lbl2.Foreground = Brushes.Gray;
            lbl3.Foreground = Brushes.Gray;
            panel1.Visibility = Visibility.Visible;
            panel2.Visibility = Visibility.Collapsed;
            panel3.Visibility = Visibility.Collapsed;
        }

        private void Label_MouseDown_1(object sender, MouseButtonEventArgs e)
        {
            lbl1.Foreground = Brushes.Gray;
            lbl2.Foreground = Brushes.Black;
            lbl3.Foreground = Brushes.Gray;
            panel1.Visibility = Visibility.Collapsed;
            panel2.Visibility = Visibility.Visible;
            panel3.Visibility = Visibility.Collapsed;
        }

        private void Label_MouseDown_2(object sender, MouseButtonEventArgs e)
        {
            lbl1.Foreground = Brushes.Gray;
            lbl2.Foreground = Brushes.Gray;
            lbl3.Foreground = Brushes.Black;
            panel1.Visibility = Visibility.Collapsed;
            panel2.Visibility = Visibility.Collapsed;
            panel3.Visibility = Visibility.Visible;
        }
    }
}

I am also attaching my demo project. and this project is MVVM template.

MVVM project with code-behind

How to do it...

Please tell me, How to convert this to MVVM?

Vikas Gupta