Any idea on how I can add the punctuation?

I would like my email to read:

Dear John Smith,

I think I need to put in one of the two passages I quoted above. I don't know which, where or how.

By how, I mean I don't know how to code it in, even if I knew where to put it. I can kind of understand what php is doing, but I can only copy and paste it.

For instance, I understood the big clue to fix my first problem was this:
$name = $firstname . ' ' . $lastname;

Then I just had to copy/paste.

Hate to bug again, but can you help one more time?