There are two ways:
Use the multi-quote button:
Instructions here:
http://www.somersoft.com/forums/faq.php?faq=vb3_reading_posting#faq_vb3_replying
Alternatively, you can do this manually ...
The code to quote someone is:
For example:
... you can do this as many times as you want in a reply ... for example:
PHP:
Here is my response to Minxdamanx
Here is my response to Sim
Gives this result:
-------------------------------------------
Here is my response to Minxdamanx
Here is my response to Sim
-------------------------------------------
The code for a link is:
PHP:
[url=website URL]link text[/url]
For example:
PHP:
[url=http://www.google.com.au/]Google[/url]
Which gives this:
Google