html tag error checking?

[Anon]

I have a problem like this. How to check in a string if there is error in html tag: tag open but not close or tag close but wasn't open. Like this:
<B>fsdfsdf
-->error
or
dfsfoy9 </B>
-->error too
Can this be done with Regular Expression?

[Anon]

Let's me retype it:

I have a problem like this. How to check in a string if there is error in html tag: tag open but not close or tag close but wasn't open. Like this:
&lt;B&gt;fsdfsdf-->error
or
dfsfoy9&lt;/B&gt;
-->error too
Can this be done with Regular Expression?

[Anon]

Please.....