Before Update code

[jms]

Hello

I am an access novice. I have created a very simple form. The primary key is an ID number. I would like access to alert me if I accidently enter the same ID number in more than one form. I have spent several hours searching the internet for how to do this, and it appears that I need to write some code in "Before Update". I am unsure how to do this exactly, as I have tried several times and it seems to never work.
My form is called "Macintosh and McGrath". The primary key is called "ID". Can anybody help me?

thanks


jms

[SoftwareMatters]

Is your id field set to No duplicates?
If so I take it you mean you want the message box instead of the default Access message?

If not just switch on No Duplicates.