Problem at the Nissan Altima sim

I was flying over to the Nissan Altima sim, when this big, black object appeared. All of the sudden SL started lagging horribly, and now when i try to log back in, SL crashes. how do I get out of the sim when i can't even succesfuly log back in?

Ctrl-P to get up the preferences from the login screen, and under the General tab, near the top, you can check a little box that will let you pick a start location. Back out of preferences, you'll have a new blank on the login screen where you can type in the name of any sim, and you'll log in there instead.

Ok, it worked. Thank you!