when i click the sort options in my module

This error will shown :

"Failed to compare two elements in the array."

This help will greatly appricitated.

Thanks

Sorry for not being very clear.

1. I am developing my own module and it is for image slide show.

2. I am not using System.String ,numeric and IComparabel interface.

3. I am using Class  of  Imageclick event  to move the postions of the items.

4. when i click the move button it  simply displays the below error messages, not a detailed error message.

"Failed to compare two elements in the array."

Thanks.
 

Hi Bill,

Again sorry for not being very clear.

    1. My module concept:  i upload the images from fileupload to repeatercontrols with buttons( this button for move to previous or next from list(repeater  control/any selected items).

    2. My Queston : When i click the move button that same error "Failed to compare two elements in the array."
        Please see the given code for move to previous button.
        .ascx
        <asp:ImageButton ImageUrl="~/Images/Previous.gif" ID="BtnPrevious"OnCommand="Previous_Routine" CommandName="Previous"                                  CommandArgument='<%# DataBinder.Eval(Container.DataItem, "ItemId") %>' runat="server" />

        .ascx.cs
protected void Previous_Routine(object sender, CommandEventArgs e)
        {
            Controller obj = new Controller();
            List<Info> lstItems = objs.Gets(this.ModuleId);
            lstItems.Sort();
            int Sorter = 0;
            foreach (Info obj in lstItems)
            {
                obj.SortId = Sorter;
                objs.Update(obj);              
                Sorter++;
            }
            for (int i = 0; i < lstItems.Count; i++)
            {
                Info obj = (Info)lstItems[i];
                if (obj.ItemId == Convert.ToInt32(e.CommandArgument.ToString()))
                {
                    if (i == 0)
                    {
                        break;
                    }
                     obj.SortId--;
                     objs.Update(obj);                

                     obj = (Info)lstItems[i - 1];
                     obj.SortId++;
                     objs.Update(obj);                   
                }
            }

            //refresh cache
            SynchronizeModule();

            ExportXml(false);

            Response.Redirect(Request.Url.AbsoluteUri, true);
}

Thanks