Check for match

On my Access form called frmMain, I have a field called Roll# which is a 15-digit text field. The record source of this form is qryMain. I would like code that will check to see whether the current 15-digit roll number from frmMain exists in the 'Roll#' field of a different table called tblSales. If the code finds a matching roll number in tblSales, I would like to be notified, either by perhaps changing the color of the Roll# field on frmMain from black to green, or perhaps by displaying a message on the form (not a MsgBox). I am a newbie so I hope I have described this clearly enough. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform winxp and access 2002