Difference between two date in same column of two consecutive raw

[latifju]

I am new in access 2010. for my official work I need to build a report but I can't cause I don't know how to do that. My table like below

ID	startDate	Dr	Cr
1	12-JAN-12	12,000	0
2	13-JAN-12	50,000	2,500
3	15-JAN-12	1,00,000	50,000
4	16-JAN-12	25,000	30,000

I want my report or query like bilow

ID	startDate	Dr	Cr	Dr_Cr	DateDiff	Product
1	12-JAN-12	12,000	0	12,000	1	12,000
2	13-JAN-12	50,000	2,500	47,500	2	95,000
3	15-JAN-12	1,00,000	50,000	50,000	1	50,000
4	16-JAN-12	25,000	30,000	-5,000	0	0

The red column is the problem for me in query. What can I do for the red colum. If I can do it in query it will be very short proccess or I have to leave this access report. Please some help me to find out the solution for the problem.

Thanks for your help
Abdul Latif
Bangladesh

[alansidman]

Try this:

SELECT table1.Id, table1.StartDate, table1.Dr, table1.Cr, [Dr]-table1.Cr AS Dr_Cr, DLookUp("StartDate","table1","[ID]=" & [ID]+1) AS [Prior], NZ(DateDiff("d",[StartDate],[Prior]),0) AS Difference, [Dr_Cr]*[Difference] AS Product
FROM table1;

[latifju]

Thanks, Its works.... , One more problem if Raw 3 (means ID = 3) deleted than what will be?