pre_replace not sure what the correct expression is

Hi all

I need to scan a block of body copy that will replace certain words within the copy with other words.

I can do this is and got this part working.

How ever i need it to replace only words out side of any html tags. <.> </.> < />

So if the word appears in a link its ignored.

Any ideas on how to do this?

my code so far



$patterns[] = '/'.$tag.'(?![^<]*>)/i';
$replacements[] = '<a  href="'/'.$tag.'"  >'.$tag.'</a>';


Thanks