The following sections describe the formulas that you can enter into the Copy/Calculate and Edit/Match fields on the Field Description screen.
A formula is a sequence of one or more statements separated by a new line or ;. A formula calculates a value that becomes the new value of the field (for Copy/Calculate formulas), or is an error message (for Edit/Match formulas). Each statement calculates a value; the value of the formula is the value of the last statement evaluated.
For example, the formula
quantity * price
has one statement, an expression, that calculates the quantity times the price.
The formula
if cost >= 100.00
"cost must be less than $100.00"
else
""
endif
returns either the string cost must be less than $100.00 (if the cost field is greater than or equal to 100.00), or the empty string. Since the else part returns an empty string, you can leave it out. The following formula has the same result
if cost >= 100.00
"cost must be less than $100.00"
endif
This example could also be written as
if cost >= 100.00; "cost must be less than $100.00" endif