Button Animation

  <Button Content="myButton" Width="50" Height="50">
    <Button.Triggers>
      <EventTrigger RoutedEvent="Button.MouseEnter">
        <EventTrigger.Actions>
          <BeginStoryboard>
            <Storyboard>
              <DoubleAnimation Storyboard.TargetProperty="Width"
                               From="0" To="100" Duration="0:0:2" />
              <DoubleAnimation Storyboard.TargetProperty="Height"
                               From="0" To="100" Duration="0:0:2" />
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger.Actions>
      </EventTrigger>
    </Button.Triggers>
  </Button>