Dear Expert

I am trying to convert my single user system to multiuser system.

I wrote follwing codes behind SAVE button.

Do not know that are reliable or not.

Please review and help me

sno1=thisform.text1.value
	date1=thisform.text2.value
	code1=thisform.text4.value
	partyname=thisform.text5.value

*--- delete current invoice if found
	select sales
	delete all for sno=thisform.text1.value in sales
	tableupdate(.t.,.t.,'sales')

*--- get NEW sno (refresh sno if some one has saved invoices greater than text1.value)
	maxsno=0
	calculate max(sno) for !deleted() to maxsno
	thisform.text1.value=maxsno+1

	Begin transaction

		*---prepare credit entry
			select  temp
			repl all credit with round(credit,0),type with [P],detail with thisform.text3.value,;
				sno with thisform.text1.value,dates with date1,	code2 with code1,;
				credit with round(credit,0),edmode with .t. for !empty(codes)

			update temp set names =products.names from products where temp.codes=products.codes

			select sales
			append from dbf("temp")  for !empty(codes) and !deleted()

			result=tableupdate(.t.,.t.,'sales')
			
			*---error trapping routine
			if !result
				= aerror(laerror)
				tablerevert( .t., "sales" )
				= messagebox('Error #' + ltrim(str(laerror[1])) + ': ' + laerror[2] + ;
					' occurred while saving.')
			endif result

		*---prepare debit entry
			select temp
			repl all code2 with codes, codes with code1,names with partyname,detail with thisform.text3.value,;
				sno with thisform.text1.value,debit with round(credit,0),;
				credit with 0 type with "" ,edmode with .t. for !empty(codes)

			select sales
			append from dbf("temp")  for !empty(codes) and !deleted()

			result=tableupdate(.t.,.t.,'sales')

			*---error trapping routine
			if !result
				= aerror(laerror)
				tablerevert( .t., "sales" )
				= messagebox('Error #' + ltrim(str(laerror[1])) + ': ' + laerror[2] + ;
					' occurred while saving.')
			endif result

	end transaction

	flush in sales force