thanks for fast replay, I made the sql the same you told me but I ound the fields which has value is converted to a (*) otherwise it is 0
and this is my code which I have done.

mdate1="01/03/2002"
mdate2="31/03/2002"
mdate1=ctod(mdate1)
mdate2=ctod(mdate2)
SELECT Gl.grpcode, Accgroup.grpname, Gl.accno, Gl.macc, Gl.fsacc, Gl.ssacc,;
Gl.tsacc, Gl.desc, Subtrn.debit, Subtrn.credit, IIF(Subtrn.debit-Subtrn.credit>0,Subtrn.debit-Subtrn.credit,0) as balancedebit,;
IIF(Subtrn.credit-Subtrn.debit>0,Subtrn.credit-Subtrn.debit,0) as balancecredit;
FROM accgroup,gl,subtrn,trans;
where Gl.grpcode = Accgroup.grpcode ;
and Subtrn.srno = Trans.srno ;
and Gl.accno = Subtrn.accno;
and Trans.trdate >=mdate1 and Trans.trdate <=mdate2;
ORDER BY Accgroup.grpcode,Gl.accno

thanks