internal static void AppendCheckBoxFilter(int index, JqGridFilter filter, ref string filters)
 {
     filters += CheckBoxFilter.
         Replace("{INDEX}", index.ToString()).
         Replace("{PROPERTY}", filter.Property).
         Replace("{COMPARER}", filter.Comparer.ToString());
 }
 internal static void AppendSelectFilter(int index, JqGridFilter filter, IList options, ref string filters)
 {            
     filters += SelectFilter.
         Replace("{INDEX}", index.ToString()).
         Replace("{PROPERTY}", filter.Property).
         Replace("{OPTIONS}", CreateOptions(options)).
         Replace("{COMPARER}", filter.Comparer.ToString());
 }