Thanks colucix

I had never heard of paste command in unix. This really helpful command. I was thinking of writing a code to accomplish this. But this command really eased all my presssure.
However I am facing some problem with this command as well.
I ave following two files
$cat account_name
quantsre
fnguide
paclife
$cat success_internal
Internal: 14/07/2008 21:10:58 (10.56.208.18)
Internal: 09/06/2008 13:18:48 (10.2.104.147)
Internal: 07/07/2008 11:52:04 (10.2.200.89)
when i use paste command as specified by you i dont get expected result though
$paste -d, account_name success_internal
,Internal: 14/07/2008 21:10:58 (10.56.208.18)
,Internal: 09/06/2008 13:18:48 (10.2.104.147)
,Internal: 07/07/2008 11:52:04 (10.2.200.89)
whereas expected result was
quantsre,Internal: 14/07/2008 21:10:58 (10.56.208.18)
fnguide,Internal: 09/06/2008 13:18:48 (10.2.104.147)
paclife,Internal: 07/07/2008 11:52:04 (10.2.200.89)
I am using Solaris 5.8, bash shell. I will try it on linux box in some time.
-Ravi