Share something by email on windows phone 8

In xaml file, let's say we have a button like this:

     <Button x:Name="tellAFriendButton" Width="352" Height="47"   
         Click="OnClickTellAFriendButton"  
         Style="{StaticResource TellAFriendButtonStyle}" Margin="174,241,274,0"   
         Template="{StaticResource TellAFriendControlTemplate}">  
     </Button>  

In c#:

     private void OnClickTellAFriendButton(object aSender,  
         System.Windows.RoutedEventArgs aRoutedEventArgs)  
     {  
       var emailAddressChooserTask = new EmailAddressChooserTask();  
       emailAddressChooserTask.Show();  
       emailAddressChooserTask.Completed +=  
                     EmailAddressChooserTaskCompleted;  
     }  
     void EmailAddressChooserTaskCompleted(object aSender,  
                     EmailResult aEmailResult)  
     {  
       var emailComposeTask = new EmailComposeTask();  
       emailComposeTask.To = aEmailResult.Email;  
       emailComposeTask.Body = ComposeEmailBody();  
       emailComposeTask.Show();  
     }  

Where composeEmailBody() is a function that returns a string, you can implement it in your own needs.