Wordpress Embed PDF Shortcode

functions.php

// Embed PDF File using shortcode
// Usage- [embedpdf 

function embedthepdf($atts, $content = null) {
        extract(shortcode_atts(array(
            "id" => 'default-embed',
            "url" => 'http://samplepdf.com/sample.pdf',
            "width" => '990px',
            "height" => '743px'
        ), $atts));
        return '<iframe id="' . $id . '" src="http://docs.google.com/viewer?url=' . $url . '&embedded=true" style="width:' . $width . '; height:' . $height . ';" frameborder="0"></iframe>';
    }
    add_shortcode('embedpdf', 'embedthepdf');