' "deb' file is not known [duplicate]

I am relatively new to Ubuntu and especially to using terminal commands. I love the system and regret not having discovered it years ago.

In playing around with it and tweaking my system (Ubuntu 13.04) I have somehow lost control of my terminal function. When I attempt to run a command in the terminal I get an error msg.:

E: Type '“deb' is not known on line 1 in source list /etc/apt/sources.list.d/virtualbox.list
E: The list of sources could not be read.

Is there any way for me to regain control of the terminal and/or stop the "virtualbox error?"

Run sudoedit /etc/apt/sources.list.d/virtualbox.list, remove the " at the beginning of the first line, save and close. All done.