I HV ALREADY USE THE METHOD THAT MR. Mark Mccasland TAUGHT ME YESTERDAY.
BUT I STILL GOT THE SOME PROBLEM.
MY CODING IS:

With Thisform.GRID
.recordsourcetype = 4
.recordsource = 'SELECT SOHEAD.SO_NO, SODETAIL.SO_NO FROM SOHEAD JOIN SODETAIL ON SOHEAD.SO_NO = SODETAIL.SO_NO WHERE SODETAIL.SO_NO = SONO INTO CURSOR RESULT'
EndWith

"SONO" IS THE EXCATLY MUNBER THAT I WANT TO DISPLAY~
ALSO I USE A SIMPLE SQL STATMENT , STILL CAN'T DO THAT,
SIMPLE SQL STATMENT:

With Thisform.GRID
.recordsourcetype = 4
.recordsource = 'SELECT SODETAIL.SO_NO FROM SODETAIL WHERE SODETAIL.SO_NO = SONO INTO CURSOR RESULT'
EndWith

I HV NO IDEA ON THIS, CAN ANYONE GIVE ME A HAND?!
THX