I am a newbie in PHP. I like to have one question about how to check for specific text on any web page.

I have a dating site. I deleted some members but they are still indexed on Google so I want to enter a message on my webpage for those who are no longer existed on my database. Also, I have ads on my site, I don't want to place ads on these non-existing members pages.

If you look at this:

There is an error message about "Member was not found"

This is what I did but it didn't return anything:

<?php } if (strpos($error_message, 'Member was not found') != false) { ?>
<p>Welcome to Vietdating.us</p>

How do I check for this text "Member was not found" on any web page, it it is found, then enter my own message.