<Button Content="Button" HorizontalAlignment="Left" Margin="41,240,0,0" VerticalAlignment="Top" Height="41" Width="110">
<Button.Template>
<ControlTemplate TargetType="Button">
<Grid>
<Border x:Name="Border"
Width="{TemplateBinding ContentControl.Width}"
CornerRadius="20">
<Image Source="Resources/button.png" Height="41" Width="110" Stretch="Fill" Cursor="Hand">
<Image.Style>
<Style TargetType="{x:Type Image}">
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Source" Value="Resources/button2.png" />
</Trigger>
<Trigger Property="IsMouseOver" Value="False">
<Setter Property="Source" Value="Resources/button.png" />
</Trigger>
</Style.Triggers>
</Style>
</Image.Style>
</Image>
</Border>
</Grid>
</ControlTemplate>
</Button.Template>
</Button>