Accumulation

[nizamsha]

Hi All

date and properties as dimension 

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

I have the following straight table what i want is  this

Date	Properties	Value	result
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

in properties i have ac,fridge,tv and lcd .. in result i have some values ..how we r calculating the result is in properties field i have ac  for that i have result is 30. like wise i have fridge for that result is 20 but now is the point again in properties i have ac so .so already i hve value for ac is 30 but now i have 40 so it should sum 30+40 and display the result 70 like wise fridge too