status.i4.v = winbox( wid.i4.v, up_row.i4.v, nrows.i4.v, left_col.i4.v,
'winbox_c' is a C callable (by value) windowed version of INBOX.
It will return TRUE if the color TV cursor was in a specifed box the
last time the INTYPE routine was called. The box is specified by a
window ID 'wid', a starting row inside the window 'up_row', a number of
rows 'nrows', a starting column inside the window 'left_col' and a
number of columns 'ncols'.
'wid' is the window ID of the window to test as returned by
the WMAKE or 'wmake_c' routine.
'up_row' and 'left_col' are the row and column within the window. The
top left character inside the window border is row 1, column 1.