VARIABLE.l2.v = IMSURE(IROW.i2.r, ICOL.i2.r, NSECS.i2.r)

	This logical function writes the word CAUTION in yellow starting
	at the designated screen position, (ICOL,IROW). The routine then
	waits NSECS seconds for a keyboard interrupt. If the interrupt
	occurs within the specified time interval and the visible cursor
	is under the word CAUTION then a logical value of TRUE is
	returned and the original contents of the display field are
	restored. If there is no keyboard interrupt in the specified
	time interval or if there is but the visible cursor is not under
	the CAUTION then the word REJECT is displayed in red. After one
	second the original contents of the display field are restored
	and a logical value of FALSE is returned to the caller. The
	specified display position must allow for a field width of eight
	(8) characters. The method of implementation may change in
	future versions of this routine.