updating most recent entry, regardless of previous records in database

[PreethiGowri]

I have a login table which as columns name, employee_id, date,login, logout; everything works fine until a regular updation of login and logout is done(i.e every login having a logout). my problem is when the person forgets to logout, and next session or next day he login's and again logout's the previous un-updated cell also gets updated which should not happen.

Result obtained now:
When the person forgets to logout and login's again

    name      emp_id  date       login        logout
    Preethi    002   1/11/13    09::0:00     00:00:00
    preethi    002   1/11/13    12:24:13     00:00:00

later logout result

    name      emp_id  date       login        logout  
    Preethi    002   1/11/13    09::0:00     10:15:54  
    preethi    002   1/11/13    12:24:13     10:15:54

Expected result:

    name      emp_id  date       login        logout
    Preethi    002   1/11/13    09::0:00     00:00:00
    preethi    002   1/11/13    12:24:13     10:15:54

[PreethiGowri]

I solved my problem,
here is the code -

update table_name set logout = now() order by sl desc limit 1

sl(serial number) is a column for ordering