Set key to be default to sign/encrypt

[Csabi]

Hi all!

I created a new keypair now and i would like to set this new keypair
to my default keypair.
How can i do it?
GNUPG using my older key to sign/encrypt messages.
The default-key option in gpg.conf is not operate me, if i using it
then the following error message appear: Failed to sign, secret key is
not available.
How can i set this new keipair to be default?

Best regards, Csabi