ggwp/GGwp/Page/Authoriz.xaml

<Page x:Class="GGwp.Authoriz"
      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" 
      xmlns:local="clr-namespace:GGwp"
      mc:Ignorable="d" 
      d:DesignHeight="450" d:DesignWidth="800"
      Title="Authoriz">

    <Grid>
        <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" Width="350">
            <TextBlock HorizontalAlignment="Center" Text="Логин"/>
            <TextBox Background="#0000" Name="EnteredLogin"/>
            <TextBlock HorizontalAlignment="Center" Text="Пароль"/>
            <TextBox Background="#0000" Name="EnteredPass"/>
            <Button Name="AuthUser" Click="GoAuth" Margin="0,10,0,0" Content="Войти"/>
            <TextBlock Margin="0,5,0,0" HorizontalAlignment="Center" Text="ИЛИ"/>
            <Button Name="AuthGuest" Click="GoGuest" Margin="0,5,0,0" Content="Войти как гость"/>
            <StackPanel Margin="0,10,0,0" Visibility="Collapsed" Name="Capa">
                <Image Source="\Pictures\capcha.png"/>
                <TextBlock Text="Введите текст с картинки"/>
                <TextBox Name="CapaText"/>
            </StackPanel>
        </StackPanel>
    </Grid>
</Page>