$re = '/^(?!0\.00)\d{1,3}(,\d{3})*(\.\d\d)?$/m';
$str = '100.00
1,000.00
100,000.00
1,000,000.00
00.7
0.00';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php