>I have two tables (A and B) and in Table A there are to fields (IDRespG and IDRespP varchar(13) both) and in table B I have the IDUser (varchar(13)) and UserName
>

>TABLE A:
>IDRESPG    IDRESPP
>22222222    11111111
>11111111    73161768
>
>TABLE B:
>
>IDUSER   USERNAME
>11111111 Peter G
>22222222 Charles D
>73161768 Vicky B
>

>So, the output should be:
>

>Charles D  Peter G
>Peter G     Vicky B
>

Try

select TA.UserName as First_User, TB.UserName as Second_User 
from TableA Descr INNER JOIN UserName TA 
ON Descr.IDRESPG = TA.IDUSER ;
INNER JOIN UserName TB 
ON Descr.IDRESPP = TA.IDUSER ;