What I'm creating is a forum.

What is the best way to block problems in a user message.
For example I do not want them inputing their own HTML:
Code:
<B><I>
Also, no Javascript:
Code:
<SCRIPT> 
 open infinate windows
</SCRIPT>
ect.
Do you see what I mean?

I hird a while ago of a command called [scriptblock]
but that is not poping up any search results on this forum or google.

I don't want my forum running any JS code, or even html for malicious potential. I might eventualy add [b] tags and such in time for formating.

Thanks for the help!