To configure a field update:
Choose an object field in the Field list.
Assign the value in the Value field as follows:
To enter a static value, select a value from the list, select a date and time from the calendar, or calculate it.
To enter text or dynamic value, click the Expression Builder button and use the Build Expression window to type in your text or enter a SQL expression or script. The expression or script must return a single value of the same data type as the type of the field to update.