<http://schema.org/query-input>
"required name=search_term_string"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.codingforums.com/post-a-php-snippet/205066-youtube-mp3-conversion-php-class-script-4.html?s=e9b040bee392bb9e74e18c1f31c9dd48>