urgent...how to use two tables..

HI experts ..

I have a report where i am retriveing the data from table konv based on the data from the tables VBAP and VBAK..

and i have my select statment as

SELECT knumv

kposn

kschl

kbetr

FROM konv INTO TABLE it_konv

WHERE

knumv = vbak-knumv AND

kposn = vbap-posnr.

But i need to use FOR ALL ENTRIES. so can you please help me out how do i retrieve this data from KONV based on both the conditions. also i have already written seperate select queries for VBAP and VBAK.