Using the Visual State Manager in Silverlight Templates: Listing 1
<Style x:Key="ButtonFlatStyle" TargetType="Button">
<Setter Property="Width" Value="100" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid>
<Border Width="{TemplateBinding Width}"
Height="{TemplateBinding Height}"
Background="{TemplateBinding Background}"
CornerRadius="8" BorderBrush="Black"
BorderThickness="1">
<ContentPresenter
Content="{TemplateBinding Content}"
HorizontalAlignment="Center"
VerticalAlignment="Center" />
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>