I have a website where members can input text using a limited subset of HTML.  When a page is displayed that contains a user's text, if they have any unclosed tags, the formatting "bleeds" across into the next area.  For example, if the user entered:
Hi, my name is <b>John
Then, the rest of the page will be bold.
Ideally, there'd be someting I could do that would be this simple:
<div contained>Hi, my name is <b>John</div>
And no tags could bleed out of that div.  Assuming there isn't anything this simple, how would I accomplish a similar effect?  Or, is there something this easy?
Importantly, I do not want to validate the user's input and return an error if they have unclosed tags, since I want to provide the "easiest" user interface possible for my users.
Thanks!