$re = '`id="selectNOIOrg_do_frm_organization{([^{}\n]+)}"`m';
$str = '<input type="radio" name="frm.organization" id="selectNOIOrg_do_frm_organization{C5DF28FD-26EF-90DA-1214-BD72E0214F17}" value="{C5DF28FD-26EF-90DA-1214-BD72E0214F17}" title="College of St. Jude" ext-ns-multiple="frmorganization">
';
preg_match_all($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