Open the Formula window in one of the following ways:
Click and select the formula you want to change.
Make changes as needed.
To change the formula name, click [Rename] and enter the new name in the Formula field.
For more information, click on the title
bar of the window, and then click a field or button.
When you finish changing the formula, click [OK] to save it.
Test the formula to make sure it works properly. How?