Set dropdownlist select value in gridview

Dim vProduct As DropDownList = DirectCast(sender, DropDownList)
        Dim vProductID As Integer = vProduct.SelectedValue
 
        Dim mtg As ConnectionStringSettings = ConfigurationManager.ConnectionStrings("TMCdb")
        Dim connection As New SqlConnection(mtg.ConnectionString)
        Dim cmd As New SqlCommand("Select FactoryID from tblProducts WHERE ProductID = " & vProductID & "", connection)
        Try
            connection.Open()
            Dim vFactoryID As Integer = cmd.ExecuteScalar
            Session("FactorID") = vFactoryID
            CType(gvOrderDetails.FindControl("cboFactoryID"), DropDownList).SelectedValue = vFactoryID
            connection.Close()
        Catch
        End Try