[Dev-C++] C++ dialog control

[Chris S. <CS...@Ai...>]

I have created an OK pushbutton in a dialog box via a resource script =
(see code below):=20

****

    DEFPUSHBUTTON   "Start", ID_START_CALC, 255, 7, 50, 14
    DEFPUSHBUTTON   "OK", ID_OK, 255, 27, 50, 14
    DEFPUSHBUTTON   "Cancel", ID_CANCEL, 255, 47, 50, 14
****

I am trying to grey it out and disable it, from within a callback =
function, while I carry out some calculations, and then enable it again =
when the calcs are complete.=20

Does anyone know how to do this? I have tried SendDlgItemMessage with =
the dialog's handle, the pushbutton's ID and various LPARAMs and WPARAMs =
but with no success. I have also trawled www.msdn.microsoft.com but =
found no suggestions.=20

Regards=20
Chris Sroka=20