Problem with apt-get and sources.list

[Amr Saber]

Hi there,
While I was configuring some thing in the sources.list file as apt-get
couldn't get any package I wanted or asked for (I double checked the
spelling for each package) and it just said package not found ...
any way, The problem is that the sources.list file was accidentally deleted
and I can't find any version of it online and ofcourse the apt-get is no
longer working at all