Why does my wpf-grid ignore Grid.Row?

Question

I have the following code:

<Popup Name="enterNamePopup" Width="250"  Height="200" AllowsTransparency="True" Placement="Center"  IsOpen="true">
        <Grid Background="Aquamarine">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="120" />
                <ColumnDefinition Width="120" />
            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition Height="7"/>
                <RowDefinition Height="20" />
                <RowDefinition Height="30" />
            </Grid.RowDefinitions>
            <TextBlock Name="PleaseEnterName" Foreground="Black"  Grid.Row="1" Text="Save as..." Grid.ColumnSpan="2" />
            <TextBox Name="ProjectNameTextBox" Visibility="Visible"   Grid.Row="2" Grid.ColumnSpan="2" />
         <Button Name="SaveProjectButton" Content="Save Project" Grid.Row="3"  Grid.Column="1"/>
            <Button Name="CancelButton" Content="Cancel"  Grid.Row="3" Grid.Column="2" />

        </Grid>
    </Popup> 

Can anyone tell me why it looks like this When i want to have something like this

Answer 1

You only have three RowDefinitions. They will be numbered 0, 1 and 2. Any row number higher than 2 will go into row 2.