[Phpwm] Securing feedback forms

[David Johnson]

Hi all,

I've got a few sites that have a simple feedback form to allow visitors to 
send feedback to a hard-coded recipient. I thought the form was secure such 
that spammers couldn't use it to send spam, but it seems I was wrong. Only 
one spam actually got sent (and it bounced) but a spammer has evidently found 
a way to insert arbitrary headers into the mails my form is generating (BCC 
etc.).

My current code is here:
http://pastebin.co.uk/4915

(btw, what happened to the PHPWM pastebin?)

I'm intending to add addslashes() to it, but apart from that is there anything 
else I can/should do to sanitise input?

TIA,
David.