removeing duplicate records in particular columns

removeing duplicate records in particular columns

i have say 5 coulmuns. i want to delete duplicate values in col1 and col2

col1      col2          col3       col4     col5

1            a             xyz     abc          eba

1            a            abv       ref          abe

1            b           kac         tyr          bas

1            c             eff        ed           bec

2            a             xyz     abc          eba

2            a            abv       ref          abe

2            b           kac         tyr          bas

2            c             eff        ed           bec

here i want to remove the row number 2 and 6

what i want is the combination in col1 and col2 should not be repeat....

thous rows should be deleted...

and i can not use any table in this process... please suggest me how can i approch to achive this task using Data flow transformations..

please suggest me

thanks...

Thanks & Regards $@m