SelectPortalInstance.xaml

<Window x:Class="DotNetSiemensPLCToolBoxLibrary.TIAV21.SelectPortalInstance"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" WindowStyle="ToolWindow" WindowStartupLocation="CenterScreen"
             Height="450" Width="800">
    <Grid>
        <ListBox x:Name="lstInstances" Margin="10,31,10,64"/>
        <TextBlock HorizontalAlignment="Left" Margin="10,10,0,0" TextWrapping="Wrap" Text="Select Portal Instance" VerticalAlignment="Top"/>
        <Button Content="Ok" HorizontalAlignment="Right" Margin="0,0,10,10" VerticalAlignment="Bottom" Width="130" Height="49" Click="Button_Click"/>
    </Grid>
</Window>