error in asp.net

In my aspx file I HAD :
<asp:AccessDataSource    id="AccessDataSource1"    DataFile="data\DBS.mdb"    runat="server" selectcommand="select * from table"    >
On my webpage I could change the language of the contents by clicking an icon, when the icon was clicked a javascript command like var sURL = unescape(window.location.pathname);  window.location.replace( sURL ); is performed.    This all work ok.
Now I changed my accessdatasource and added : <SelectParameters>                <asp:QueryStringParameter Name="Country" QueryStringField="C" />  
</SelectParameters>               </asp:AccessDataSource>
and in my codebehind I have :
 If Not Page.IsPostBack Then
            AccessDataSource1.SelectCommand = "SELECT * FROM table" 'where Country= " & Request.QueryString("C") & " order by id"
            EmployeesGridView.SelectedIndex = 0
            CustomersGridView_SelectedIndexChanged(sender, e)
        End If

But when I do this now I get an error on :
Sub CustomersGridView_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs) Handles EmployeesGridView.SelectedIndexChanged
        Dim row As GridViewRow = EmployeesGridView.SelectedRow
...
saying :
Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

What can this be and how can this be solved ??