/**
 * 检查字符串编码
 * @param unknown $keytitle
 * @return string|unknown
 */
function strencd($keytitle,$code='UTF-8'){
	$encode = mb_detect_encoding($keytitle, array('ASCII','UTF-8','GB2312','GBK','BIG5'));
	if ($encode != $code){
	return iconv($encode,$code,$keytitle);
}
return $keytitle;
}