If you remember the email address you used to register the oldf account, you can use the "forgot password" option on login to get a mail that will allow you to change password (also the account name is in the message you will get).
If you don't remember the email address you used to register, it won't be so easy to get back your account. In fact you need to give to GM enough proofs that the account was yours.
A good starting point to do so is this guide: http://www.aeriagames.com/forums/en/viewtopic.php?t=844805
It was written for hacked accounts, but should work also in your case.
There is no way you can get back your account knowing only the character names... we would be all in trouble if it was possible.