accumulation

[nizamsha]

Hi all

i have the following table 

Date	Properties	Value
11/12/12	A/c	30
11/12/12	Fridge	20
12/12/12	A/c	40
12/12/12	Fridge	30
12/12/12	TV	60
13/12/12	Fridge	70
13/12/12	LCD	40

But i want the output like this

Date	Properties	Value	total
11/12/12	A/c	30	30
11/12/12	Fridge	20	20
12/12/12	A/c	40	70
12/12/12	Fridge	30	50
12/12/12	TV	60	60
13/12/12	Fridge	70	120
13/12/12	LCD	40	40