Animations Silverlight

    xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' 
    xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
    xmlns:d='http://schemas.microsoft.com/expression/blend/2008' 
    xmlns:mc='http://schemas.openxmlformats.org/markup-compatibility/2006' 
    mc:Ignorable='d' 
    d:DesignWidth='640' 
    d:DesignHeight='480'>
                HorizontalAlignment="Center" VerticalAlignment="Center">
        Expanding Button
        
            
                
                    
                                                                 Duration="0:0:2"
                                         FillBehavior="Stop" />