<?php
$code = '';
for($i=0; $i<100; $i++)
{
$code = getNextAlphaNumeric($code);
echo "$code\n";
}
function getNextAlphaNumeric($code) {
$base_ten = base_convert($code,36,10);
$result = base_convert($base_ten+1,10,36);
$result = str_pad($result, 3, '0', STR_PAD_LEFT);
$result = strtoupper($result);
return $result;
}