need your help on Access for Formula

[hessam]

Hello

need your help on Access for Formula

how can make formula for finding total MB used from Send To User and Receive From User

From this Specified date start 2010/12/02 1:00:00 finish 2010/12/05 6:58:00

and Conversely evrey mg used Except this time start 2010/12/02 1:00:00 finish 2010/12/05 6:58:00

TotalMB Send To User+Receive From User AT Specified date start 2010/12/02 1:00:00 finish 2010/12/05 6:58:00

So if you can making it on Access please

please see attachmentHello.rar