Regular Expression For Search Functionality

I am implementing a search functionality for some static pages. My Content is in p tag’s, span, div, li’s. If I search a word which is in p tag then it get searched but except that non of the word get searched. Below is the regular expression which I am using:

preg_match_all(“/\<p\>(.)“.$_GET[‘s’].”(.)\<\/p\>/i”, $contents, $matches, PREG_SET_ORDER);

I want such a regular expression which will search all the words no matter it is in p tag, span, div or li. it should get searched.

Can someone help?

So… just find the words, huh.
$find = str_replace(" “,”|“,urldecode($_GET[‘s’]));