A special function, ct_win_inst(), is automatically called prior to each FairCom DB API call. This function automatically calls RegisterCtree(), SwitchCtree(), and UnRegisterCtree() when the Automatic Instance Support is enabled for Windows 3.1. This capability can be used without the Automatic Windows Instance logic by enabling the following define:
#define ctPREFNC ct_win_inst
This allows you to call your own function by either placing your function logic within a function named ct_win_inst or by setting the ctPREFNC define to your function name. This is useful for any type of operation done prior to each function call. However, keep in mind the overhead introduced into applications by doing time-consuming operations.