Upgrade from Xubuntu 12.04 wants to go to Ubuntu 14.04

[MR ZenWiz]

I've asked this in the Xubuntu group, but got no response.

I'm running Xubuntu 12.04 and want to upgrade to 14.04.  If I run the
update-manager (with "-d" 'cuz it doesn't see an upgrade without the
-d) it want to upgrade me to Ubuntu 14.04.

Is it possible to go from X12.04 to X14.04 or do I need to install
from disk/USB?network?

Thanks.

MR