php中英文判断

static function ischinese($s){
		 	$allen = preg_match("/^[^\x80-\xff]+$/", $s);
		 	$allcn = preg_match("/^[".chr(0xa1)."-".chr(0xff)."]+$/",$s);
		 	if($allen){
		 		return 'allen';
		 	}else{
		 		if($allcn){
		 			return 'allcn';
		 		}else{
		 			return 'encn';
		 		}
		 	}
		 	
		}