How do I calculate a variance from record to record in one dataset?

[AlanCT]

If I have a dataset as follows:

Date.    Profit

Jan 1.    $100

Jan 2.     $200

Jan 3.    $150

How can I calculate the daily change in profit, so that the new data set is as follows:

Date. Profit  Variance-from-prior-day
Jan 1. $100.    .
Jan 2. $200.    $100
Jan 3. $150.    -$50

Thanks!!

[Reeza · Accepted solution]

The DIF() function.

Var=dif(profit);