how to get row number in select query

Good morning,

For postgresql 8.3, what is the system method/key word to get row number 
please?

E.g.,

==================
lname1 gname1
lname2 gname2
lname3 gname3
......

I'd like to get

1  lname1   gname1
2  lname2   gname2
3  lname3   gname3

... ...

Something like
select row_number?, lname, gname from Table1;

Thanks a lot!


--
Lu Ying