i have a table as below				
					
	TABLE  A				
	Date	Cust No.	Item 	Qty	
	01/01/2002	A	1001	15	
	03/01/2002	A	1001	25	
	04/01/2002	A	1001	35	
	05/01/2002	B	1001	45	
	01/01/2002	A	1002	10	
	02/01/2002	A	1002	20	
	02/01/2002	B	1001	30	
	03/01/2002	B	1001	40	
	05/01/2002	B	1003	50	
             
        how do i write a SQL syntax to display a result as below or alter 
my table so that the result can display as below? what should i do? and 
can anyone give a sample code as this method?


	RESULT				
	Date	Cust	Item	Qty	As Of Date Qty
	01/01/2002	A	1001	15	15
	01/01/2002	A	1002	10	10
	01/01/2002	A	1003	0	0
	01/01/2002	B	1001	0	0
	01/01/2002	B	1002	0	0
	01/01/2002	B	1003	0	0
	 	 	 	 	 

	02/01/2002	A	1001	0	15
	02/01/2002	A	1002	20	30
	02/01/2002	A	1003	0	0
	02/01/2002	B	1001	30	0
	02/01/2002	B	1002	0	0
	02/01/2002	B	1003	0	0

	03/01/2002	A	1001	25	40
	03/01/2002	A	1002	0	30
	03/01/2002	A	1003	0	0
	03/01/2002	B	1001	0	30
	03/01/2002	B	1002	0	0
	03/01/2002	B	1003	0	0

	04/01/2002	A	1001	35	75
	04/01/2002	A	1002	0	30
	04/01/2002	A	1003	0	0
	04/01/2002	B	1001	0	30
	04/01/2002	B	1002	0	0
	04/01/2002	B	1003	0	0

	05/01/2002	A	1001	0	75
	05/01/2002	A	1002	0	30
	05/01/2002	A	1003	0	0
	05/01/2002	B	1001	45	75
	05/01/2002	B	1002	0	0
	05/01/2002	B	1003	50	50


thanks!