Setting Grouping Ranges and Intervals To specify the value or range of values that begin and end a particular group, you use the GroupOn and GroupInterval properties in the Sorting and Grouping box. These properties work hand in hand. If you are making a report that groups records on a Date field, then you can separate a year's records into four quarterly periods by setting GroupOn to Month and GroupInterval to 3 . Each Value allows you to group records containing the same value in the field or expression, Prefix Characters allows you to group on records with the same first n characters. You use expressions to get information that you cannot get directly from the tables in a database.
Most calculated controls use an expression.
An expression might calculate and display the total sales of an employee for one month. The result of an expression is not stored, but is calculated each time the report is printed or previewed. People often use text boxes to calculate values, but any control that has a ControlSource property can be used. Two common expressions add the current date or page numbers to your report. Printing the Current Date You frequently need to print the date on which a report was made.