Remove parameter from the URL query string.

gistfile1.txt

if ( ! function_exists('remove_url_parameter') )
{
    /**
     * Remove given parameter from the given url str
     */
    function remove_url_parameter($url, $key = false)
    {
        return preg_replace( '/'. ($key ? '(\&|)' . $key . '(\=(.*?)((?=&(?!amp\;))|$)|(.*?)\b)' : '(\?.*)').'/i' , '', $url);
    }
}