using name merge tags

Hi,

I want to know how to add the name filed tag to personalise the email. I had used the name merge tag and send a test email but the merge tag $[FNAME]$ showed after Dear ($[FNAME]$) instead of the customer name.

Also I want to add the date of joining for each customer to the email, are their any tags for it or how do i do that?

Thanks for the help.

Regards,
Shrikant