Simple php lottery code

/**
 * "Lottery" function
 *
 * @param integer $first starting number
 * @param integer $last ending number
 * @param integer $total number of winners
 *
 * @return string
 *
*/
function isWinner($first, $last, $total)
{
 $winner = array();
 for ($i=0;;$ i++)
 {
 $number = mt_rand($first, $last);
 if (!in_array($number, $winner))
 $winner[] = $number; // If the number is not in the array, replace it Add to array
 if (count($winner) == $total) break;
 }
 return implode(' ', $winner);
}

// for test
echo isWinner(1, 100, 5);
?>

php