Why not just build it with and AfterUpdate on the first/last name entry?

thanks Alex, I will google AfterUpdate as I'm fairly new to Access. Been using Excel over 20 years and recently converted my DB. I'm assuming there would be some VB in there somewhere also.

AfterUpdate

any chance of help with the code? lets say the fields are fname lname and email so go to afterUpdate and set the event to kick off after the lname is typed and clicked. I need to grab the first character from the fname and the complete Lname and add the "@xyz.com" to the string and input it into email on the form.

If Lname="" or Fname = "" Then
'Do Nothing
Else
  email = Left([fname],1) & lname & "@xyz.com"
End If

your the man! that works great on new records. So my next big question is what is the best way to update the existing records to add the email. I tried going through a existing record hitting enter after the lname field but no change what am I missing?

BTW it does work if I mod the record in the form

after update fires on change, you can simply add a letter and backspace it then tab to fire it, or if you have a lot of records, probably best to use a recordset for going through everything once and setting them.

Actually an update query is going to be a lot simpler for you.

Update Queries if you want more info :P

If you have nulls, might need to bring in fname and lname and set criteria to not isnull

OK playing devils advocate here.  Things to consider.

You probably don't want this to fire every time you make a change.  I would only make the email in the event that the email field is blank.  
If email <> "" then Exit Sub  
I can't imagine you want  emails changing all the time.

Before you go creating that email I would put a check in place to see if it already exists.  What would happen if you have a Jim Smith employed then you hire on Joan Smith? Who gets the [email protected] email?

What happens to Debbie Peterson's emails when she gets married and her name changes to Debbie Jones? Does the email change? Keep her old one?

This seems easy and straight forward on the face of it but you should plan ahead.

Good points Scott, you could make it complex and DLOOKUP the email before it assigns it to make sure it doesn't exist, and if it does, to add a number to the end, but then you have to check for [email protected] etc. too :P it gets fun quick. You can do it, but you need to decide how you want to handle it first.

Yeah, input masks are not good for email addresses. Go with what the guys are suggesting.