Search Website For String

<?php

$link = "http://www.somesite.com";
$ch = curl_init($link);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$page = curl_exec($ch);
$search = strpos($page, "YOUR_SEARCH_STRING");

if ($search == false) {
    echo "no";
} else {
    echo "yes";
}

?>