Hi, I am working on Property Page of a filter. I have added a ListBox in the property page to hold items for video resolution. Among the items in the list, there is one item called User Defined. I am trying to get a functionality where in, if I select User Defined in the ListBox, this selection will enable 2 Edit Control boxes so that the user can fill in Height and Width. Now, if I deselect User Defined and select some other item in the ListBox, the Edit Control boxes should be disabled. How do I do it programatically in the OnReceiveMessage() function? Please let me know. I have been trying to enable the disabled Edit Control Boxes using, SendDlgItemMessage(hList, IDC_RATE3, WM_ENABLE, (WPARAM)TRUE, 0); But this does not work. Thanks, Taklu