Assign A Foreign Key As A Parameter

hi everybody

I have the following asp.net2.0 codeSelectCommand = "Select IDEmp, FirstName,MiddleName,LastName, Date,HoursNumber, Description

From Employee, WorkOnCategory , CatDesignItemReference

where IDEmp =IDEmplWork AND FirstName = @FirstName AND Category = @AnyCategory AND ">

 

<SelectParameters>

<asp:ControlParameter ControlID="txtEmployeeName" DefaultValue="" Name="FirstName" PropertyName="Text" Type="String" /> <asp:ControlParameter ControlID="DropDownList1" DefaultValue="" Name="AnyCategory" PropertyName = "SelectedValue" Type="String" />

</SelectParameters>

 

</asp:SqlDataSource>

 

The problem is that the AnyCategory in my DropDownList1 refers to a key but unfortunalely my code understand it as string so it assigns

 Category = @AnyCategory  as if Category ='AnyCategory ' not as Category = AnyCategory 

 So what should I do

Thanks