need regular expression pattern

[anoopmail]

how can we extract 189 from http://www.google.com?hs=189&id=100

i think preg_match() is the solution , but not hav enough idea abt reg. expresions.

thanks in advance..

[Installer]

$url ='http://www.google.com?hs=189&id=100';
$url_parse = parse_url($url);
parse_str($url_parse['query']);
echo $hs;  // 189