ErrorMessageWindow.xaml

<Window x:Class="FlightGearTestExec.ErrorMessageWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:FlightGearTestExec"
        mc:Ignorable="d"
        Title="ErrorMessageWindow" Height="250" Width="400">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="6*"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
        </Grid.RowDefinitions>
        <TextBlock TextAlignment="Center" Grid.Row="0" FontSize="17">
            Connection Failed!<LineBreak/>
            Please Verify your IP and Port number<LineBreak/> 
            and verify that FlightGear is running<LineBreak/>
        </TextBlock>
        <Button Content="OK" HorizontalAlignment="Center" Grid.Row="1" VerticalAlignment="Top" Height="30" Width="Auto" Click="Button_Click"/>
    </Grid>
</Window>