Ending a partol??

[navy_gunner]

I always seem to have the "slow cousin at the party" kind of questions, so why not break the tradition!
I couldnt get my SH3 to work with vista (even trying all the steps posted on this site) so I went down to my local computer store and scored a copy of the SH4 with the u-boat missions. Seems alright of a game. Not the same, but I am sure I will get used to it with time. Snazzy graphics.
Anyhow, I have figured out all the basics..... leave port, get where I am going, muck up the Japanese navy, survive their counter-attacks and what not, but now I am stumped by the simplest of all problems.
I haul butt back to base, but there is no "end patrol" option ever. I can "quit to main menu" I thing the message is, but it comes up as a player terminated mission, and I do not know how to resume that career.
Again, I am sure its something so easy Helen Keller could figure it out even without her German shepherd, but I wouldnt mind knowing please.
Thanks in advance!