Unable to login after using kill -9 -1

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http://askubuntu.com – I was using my Ubuntu when suddenly, probably due to a lot of processes running, it stopped working. So I did Ctrl+Alt+F1, and then searched for a command to kill the process which was causing all the trouble. I am a novice, so I thought that maybe "kill" might be some command to kill some process. So I typed "man kill". There I saw "kill -9 -1" as a command to kill all processes I can. I had never thought that it will permanently kill some important processes. Now when I try to log in, a message comes displaying Failed to load session "ubuntu" Please help. (HowTos)