Prblem to use Microsoft.Windows.Design assembly reference!

Hi

i'm creating a sample custom property dialog via this link, but at compile time i'm facing some errors like this :

he type or namespace name 'IProvideAttributeTable' could not be found (are you missing a using directive or an assembly reference?)

I found some resources like this, but i could not find this assembly in my "Microsoft Visual Studio 10.0\Common7\IDE\PublicAssemblies"!

does something wrong ?

thanks in advance

http://www.codeproject.com/KB/codegen/DatabaseHelper.aspx