How to get content from Div which have other HTML tags using Regexp

I have div which contain other html tags along with text

I want to extract only text from this div OR inside all html tags

<div class="rpr-help m-chm">
                <div class="header">
                    <h2 class="h6">Repair Help</h2>
                </div><!-- /end .header -->
                <div class="ier m-bsc">
                    <ul>


                        <li><a href="#videol">Repair Video</a></li>

                        <li><a href="#qa1">Repair Q&amp;A</a></li>
                    </ul>
                </div>

                    <div>
                    <br>
                    <span class="h4">Cross Reference Information</span><br>
                    <p>Part Number 285753A (AP3963893) replaces  1195967, 280152, 285140, 285743, 285753, 3352470, 3363664, 3364002, 3364003, 62672, 62693, 661560, 80008, 8559748, AH1485646, EA1485646, PS1485646.
                    <br>
                    </p>
                    </div>

            </div>

Here is my Regexp

preg_match_all("/<div class="rpr-help m-chm">(.*)</.*>/s", $urlcontent, $description);

Its working fine whenever I assign this complete div to $urlcontent variable.

But when I am fetching data from real url like $urlcontent = "www.test.com/test.html"; its retuing complete webpage script.

How can I get inside content of <div class="rpr-help m-chm"> ?

Is there any correction require in my regexp?

Any help would be appreciated. Thanks