insert ลงmysql ไม่ได้ ErrorYou have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'update,update_user) values(null,'หกดหก','หกดหกด�' at line 1

	     $sql = "INSERT INTO dept (dept_id,dept_code,dept_name,status,update,update_user)
                    values     (null,'$dept_code','$dept_name','$status','$datetime','$update_user')"; 
		$sqlquery = mysql_query($sql)or die(mysql_error());
                    if ($sqlquery){  echo"ok";
                              }else{echo"no";}