Error file with -Dates

In my upload program I have a selection screen which has the option to to store the failed entries or the updated entries on a error file for log so that in case there is any error it can be viewed later and rectified. I have hard coded that field in selection screen witha file name where its going to store the eroor log directly. everyday on a daily basis . As the eror file will be run with the upload csv file on daily basis and the eroors will be appended to the eroor file on a daily basis , I would liek to have adate on the error file showing or separting the daily error log , Like if it was run today it showuld show the error log with todays date and when it will be run tomm , it shoule start with tommorrows date and followed by the error log.

Thanks

Error log - date:--03/09/2009

jklhdladk

agsdjkahdj

asdgjka

Error log- date- 03/10/2009

hksgdhkfk

dbkhsbfjkds

ect

Thanks