php function/class needed to validate html

Hi,
I need a function/class to validate a piece of html code. Like if my html is:
$h='
<P><A HREF=URL_HERE> some text </A> other normal text <FONT FACE="arial"> More Text </FONT></P>
';
then that function/class would convert it to validate html
For example there's no " sign in the href tag, and it's in uppercase. The entire font tag needs to be dropped and replaced with <span> may be...
There could be more attributes inside the font tag, and all need to be replaced with <span> and style. Like:
<FONT SIZE=4 FACE="arial"> More Text </FONT>
Can anyone do this, or if there's a class/function already available, then please point me to it.
Thanks

 

I'd advise you to have a look at the HTML tidy extension (php.net/tidy). You can find lots of good information at devzone.zend.com/node/view/id/761.

 

Thanks for that, but that extension may not be available on some servers. This is needed for a freely redistributable script. Anything else I can use?
Thanks

 

I can write for you a class that can do what you want, but it's cost $ lol.

Cheers.

 

How complex is the HTML going to be? How many tags are there going to be? What tags will there be?

 

Most of the tags will be:
<P>, <A HREF></A>,<FONT SIZE FACE COLOR></FONT>,<IMG SRC>,<TABLE WIDTH VALIGN CELLSPACING CELLPADDING BORDER><TR><TD WIDTH VALIGN></TD></TR></TABLE>. Apart from these, BACKGROUND attribute at different places like inside <TD background=>
The values of attributes can be inside "" sign, or without those. Like:
<A HREF="URL"></A> OR <A HREF=URL></A>. There could be more like these in background, src etc...

Thanks