public void SortGridView(GridView gv, List <WACParameter> parms)
{
string srt = WACParameter.GetParameterValue(parms, WACParameter.ParameterType.ListSort) as string;
string sortDirection = ToggleSortDirection(srt);
sortExpression = srt;
IList sorted = ListSource.GetSortedList(DataProvider.SortedList, sortExpression, sortDirection);
BindGridView(gv, sorted);
}