Basic erlang question

i have downloaded and installed erlang and when i run it in the DOS i get the prompt.

i write 2+2 and then it doesbt evaluate but just goes to next row like it is an eternal loop or waitingo for input.

in the editor i write and press enter then it justs goes to the next row, also numbered 1> and doest show a result.

so it as if it doesnt evaluate at all.

have i missed something int he installment?
or am i doing somethign wrong?

using windows vista and the lastest erlang downlaod for windows.