how to add the entity datasource (EDM) to tool box

hai

I have a visual studio 2008 in data tab i can't find the EDM DATASOUCE what component will i add to get that one i want use that datasouce in the following way

<asp:EntityDataSource ID="dsSubCategory"runat="server"
   ConnectionString="name=AdventureWorksModelConnection"
   DefaultContainerName="AdventureWorksModelConnection"
   EntitySetName="ProductSubcategory"
   Select="it.[ProductSubcategoryID], it.[Name]"Where="it.ProductCategory.ProductCategoryID = @ProductCategoryID">
    <WhereParameters>
        <asp:ControlParameter ControlID="ddCategories"
       Type="Int32"Name="ProductCategoryID" />
    WhereParameters>
asp:EntityDataSource>

how can i add this Entity datasouce