Error 546 - Use only as a Callback

Use only as a Callback - You tried to explicitly call a DDT Callback function. Callback functions may only be invoked by the DDT engine or Windows. To reference it indirectly, send an appropriate window message using CONTROL SEND or DIALOG SEND. To send custom messages, be sure to use message values higher than %WM_USER+500 to avoid conflicts with other notification messages.