$re = '/<div\s\w{5}=\"print[^>]*?>[\s\S]*?<\/div>/i';
$str = '<div class="print">
<a href="javascript:window.print();" title="Print denne side"><span class="print-btn icon">P</span> Print denne side</a>
</div>
<div source="">
<div>';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php