Sorry for the dumb question, but please humour the technologically impaired (yes, that's the new term for stupid )

How do I quote someone elses messages in a reply? (Don't laugh)

Click and then click 'Add Reply'

Or just click and it will come up with the quote.

Ahhhh... ok

or click on the square shaped word balloon in the tool bar (next to the smilie) and copy and paste between these

or, type those yourself:
type [ then QUOTE, then ]
then insert the words you want to quote by either copy/paste or just typing them, then
type [, then /QUOTE, then ].

finis

thanks peg and echoes!

you got it, JustAPixie !

For anyone who might want to know even more about quoting (and multi-quoting), there's a tutorial on the subject here:
FAQ and Tutorial - Quoting and Multi-Quoting

I've never known how to multi-quote - thanks to Echoes, I've just figured it out.

To multi-quote just click on all the posts you want to quote and then when you click 'Add Reply' they are all there for you.