You can use binary search. Of a top of my head (not tested)

lnStart = 1
lnEnd = RECCOUNT()
lnMiddle = RECCOUNT()
lnRecnNo = 0
DO WHILE lnStart <= lnEnd
	lnMiddle = INT(lnStart + lnEnd ) /2)
	GOTO (lnMiddle)
	IF NOT RLOCK()
		lnStart = lnMiddle + 1
	ELSE
		lnEnd = lnMiddle - 1
		IF lnRecno > 0
			UNLOCK	RECORD lnRecno 
		ENDIF
		lnRecno = lnMiddle
	ENDIF
ENDDO	

>I’m trying to locate the next available unlocked record in a table.
>The table has about 150 records in it.
>
>When I use following code it may take 30 seconds if the 31 record is next available unlocked record and rLock() will return .T. but it is slow
>
>Sele the table
>scan
> IF rlock() = .t.
> ?rlock()
> endif
>endscan
>
>
>if I use this code it flies thru the isRlock function but will get .f. when it tries rLock()
>
>Sele the table
>scan
> IF isRlock() = .t.
> ?rlock()
> endif
>endscan
>
>What is the fasted way to do this?