$start=0, $stop=length of file(array)

# Now check the entry at $mid for my start/stop condition

$again=1

Loop-while($again=1)
    $again=0

    $mid=int(($stop - $start)/2)

    if (array[$mid] < $beg)
        $start = $mid
        $again=1
    
    if (array[$stop] > $end)
        $stop = $mid
        $again=1

End Loop