combine rows dependent on match two columns

If I have table like this

A             aa               B             bb
1              5
2              7
                                  1              7
                                  3              6

I want to make the result like this

A or B             aa               bb
1              5                7
2              7
3                                6

A or B is a column has all data avaliable in both A and B

help please Received on Tue Mar 10 2009 - 08:14:26 CDT