title: Assign geo coordinates to a pushpin
body: <p>Guys i really need your help, i have a map</p>
  
  <pre><code>xmlns:maps="clr-namespace:Microsoft.Phone.Maps.Controls;assembly=Microsoft.Phone.Maps"
  xmlns:maptk="clr-namespace:Microsoft.Phone.Maps.Toolkitassembly=Microsoft.Phone.Controls.Toolkit"
  
           &lt;maps:Map Grid.Row="0"  Tap="Onm_MapControlTap" Name="m_MapControl
              &lt;maptk:MapExtensions.Children&gt;
                  &lt;maptk:Pushpin x:Name="m_PushPin" Tap="OnPushPinTap"&gt;
                    &lt;maptk:Pushpin.Content&gt;
                      &lt;StackPanel&gt;                        
                              &lt;TextBlock Text=""/&gt;
                              &lt;Image Source=""/&gt;
                      &lt;/StackPanel&gt;
                  &lt;/maptk:Pushpin.Content&gt;
              &lt;/maptk:Pushpin&gt;
             &lt;/maptk:MapExtensions.Children&gt;
          &lt;/maps:Map&gt;
  </code></pre>
  
  <p>when i have coordinates from the geowatcher, or when i tap on the map, i wanna add those coordinates to my pushpin.</p>
  
  <blockquote>
    <p>m_PushPin.GeoCoordinate = m_watcher.Position.Location;</p>
  </blockquote>
  
  <p>An exception of type 'System.NullReferenceException' occurred for m_PushPin, i cannot understand why this PushPin is null. Can you tell me what i'm doing wrong, and how can i fix this? </p>