DataForm

I have been given an existing silverlight project to work on...
One of the .xaml pages is a DataForm which has the following .xaml

Can you see how I can solve the problem please?
Thanks

The problem is that when I run it, the error is:
The type or namespace name 'DataForm' could not be found (are you missing a using directive or an assembly reference?)


This is the .xaml
<UserControl xmlns:toolkit="http://schemas.microsoft.com/winfx/2006/xaml/presentation/toolkit"
x:Class="DataControls.DataFormTest"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Loaded="Page_Loaded">
<Grid x:Name="LayoutRoot" Background="White">
<toolkit:DataForm x:Name="formProductDetails">
</toolkit:DataForm>

</Grid>
</UserControl>

Make sure you've got the Silverlight toolkit installed from: http://silverlight.codeplex.com/. Then check to see that you've added a reference to System.Windows.Controls.Data.DataForm.Toolkit to your project.