Reports usually are based on recordsets (.RecordSource property). the recordsource may be a query or a table type recordset. Individual fields on a report may be based on other objects or functions, including domain aggregate functions (e.g. DSum). Reports them selves and object on reports (e.g. bound text boxes) also may include some properties to enhance the reporting, such as the .RunningSum Property (referd to by Telsa).
Most (or all) of this info is readily available in the help system for Ms. Access. In general, you will get a faster response for the help system than from any web/net discussion group / forum. While, at first, the "jargon" of the help systems may be a little hard to read, after you become used to it, it becomes reasonably coherent and very specific.
MichaelRed
redmsp@erols.com
There is never time to do it right but there is always time to do it over