How to use "variable" in Subject and Send to in Access E-mail

[Vivi]

Hi. I have the design when the content of the invoice is updated then the
e-mail will be sent automatically. I have no problem to send e-mail. But I
have questions in the "subject" and "Send to".

So far, the method I reference from the discussion group, the Subject and
the "Send to" is fixed. How can I have the Invoice number (primary key)
appear in the subject of the e-mail??? Also my invoice form has another
subform to keep e-mail address.
How can the automatic e-mail send to those who are in this subform???
Thanks.

 

[Vivi]

In the subject of the e-mail, finally it works.
I use "The invoice" & Cstr(Invnum) &" is created or updated"