title: Rad grid custom filtering
body: <p>How can I activate custom filtering for my radgrid?(I googled but I didn't get any proper response regarding this)
  I have a property like AllowCustomSorting  but I don't have any property regarding filtering.
  Can any one provide the way how to implement custom filtering?
  If possbile give me a sample page then I will understand.
  Thanks in advance. </p>