13.5.14 IOFOCUS Specifier (WNT, W9*)

The IOFOCUS specifier asks if the indicated unit is the active window in a QuickWin application. It takes the following form:

IOFOCUS = iof

iof
Is a scalar default logical variable that is assigned one of the following values:

.TRUE.	If the specified unit is the active window in a QuickWin application
.FALSE.	If the specified unit is not the active window in a QuickWin application

If you use this specifier with a non-Windows application, an error occurs.