Thanks Ray.
I can see how to do the file types, but the file size isn't in the list of validation types. Consequently, when the form is submitted, if the file is too large a message appears saying the emails are being sent (progress bar), then an error page 'connection reset'.
The emails are received, without any attachment.
I've tried to specify 'validated form' as the trigger for sending the emails, but this doens't work.
Cheers
Chirs