Nested IF statements to calculate increase / decrease

HI all, I'm having a problem writing a formula to calculate the day to day increase / decrease in value on some accounts.

For instance, the top part of the spreadsheet shows the value of the account on a particular day, the bottom part shows the increase / decrease on that day.

I tried to write a nested IF statement but could not get the syntax to work properly - i'm not even sure tha this is the best way to achieve the answer.

The increase / decrease on the account should only be calculated from the initial day and show and increase / decrease if the balance changes on a day.

I would be very grateful for any insight in to how to make this work.

Thanks,

Steve

Starting Balance Day1 Day2 Day3 Day4 Day5

Account 1 500 1000 300 500 1000
Account 2 300 600 100
Account 3 1000
Account 4 200 -500 -200
Account 5 300 800

Increase / Decrease on Account
Day1 Day2 Day3 Day4 Day5
Account 1 500 500 -200 200 500
Account 2 300 600 -500
Account 3 1000
Account 4 200 -700 500
Account 5 300 500

Thanks Tony, your solution was perfect! I was going round in circles. Much appreciated !