This is the first iPhone application i am working on. To use the application, the user has to login to our server. I am done with that part. Now the problem i am facing is how to logout the user from the server, deallocate all the memory and start afresh without quitting the app. After the user logs out, i want the exact same things to happen as in applicationdidfinishlaunching method. But i dont know how to go about it. The app has a tab bar which is set up in mainWindow.xib.