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Tweet to Download - Adapted from Tutorialzine.

HTML

<link rel="stylesheet" type="text/css" href="http://fonts.googleapis.com/css?family=Yanone+Kaffeesatz:400,700,300,200"/>

<div id="container">
    <h1>Tweet to Download</h1>
    <p>The button below is hidden until after you tweet. <a href="#" id="tweetLink">Try it.</a></p>
    <a href="#" class="button"></a>
    <p>Adapted from <a href="http://tutorialzine.com/2011/05/tweet-to-download-jquery/">Tutorialzine</a> | <a href="http://jenniferperrin.com/blog/jquery-twitter-tweet-to-download-button/">Read Tutorial</a></p>
</div>

CSS

/*-------------------------
    General Styles
--------------------------*/
body {
    font-family: 'Yanone Kaffeesatz';
    color: #efefef;
    margin: 20px;
    background: #2a2a2a url("http://jenniferperrin.com/image/background.gif") 0 0 repeat;
}

p { margin:10px 0; font-size: 18px; }

h1 {
    display: block;
    margin: 0 0 20px 0;
    font-size: 60px;
    font-family: 'Yanone Kaffeesatz';
    color: rgba(255,255,255,0.2);
}
    h1:hover { color: rgba(255,255,255,0.3); }

a {
    border-bottom: 1px dotted #5a7cb1;
    color: #f27011;
    padding: 0 1px;
    text-decoration: none;
}

a:hover {
    background-color: rgba(255,255,255,0.2);
    border-bottom: 1px dotted #444;
    color: #5a7cb1;
}
/*----------------------------
    Main container
-----------------------------*/
#container {
    width:450px;
    padding:10px;
    text-align:center;
    margin:0 auto;
    position:relative;
    display:block;
}
/*----------------------------
    Download Button
-----------------------------*/
.button {
    background-color: #222;
    background-image: -webkit-linear-gradient(hsla(0,0%,100%,.15), hsla(0,0%,0%,0));
    background-image:    -moz-linear-gradient(hsla(0,0%,100%,.15), hsla(0,0%,0%,0));
    background-image:     -ms-linear-gradient(hsla(0,0%,100%,.15), hsla(0,0%,0%,0));
    background-image:      -o-linear-gradient(hsla(0,0%,100%,.15), hsla(0,0%,0%,0));
    background-image:         linear-gradient(hsla(0,0%,100%,.15), hsla(0,0%,0%,0));
    border: 1px solid #111;
    color: #c6c6c6;
    cursor: default;
    display: inline-block;
    font: 18px/12px 'Yanone Kaffeesatz';
    margin: 20px;
    padding: 10px 15px;
    position: relative;
    text-decoration: none;
    text-shadow: 0 -1px 1px hsla(0,0%,0%,.8);
    vertical-align: top;
    opacity: 0;
    -webkit-border-radius: 3px;
       -moz-border-radius: 3px;
            border-radius: 3px;
    -webkit-box-shadow: 0 1px 4px hsla(0,0%,0%,.4),
                        inset 0 1px 0 hsla(0,0%,100%,.2);
   ...

JavaScript

(function($) {

    var win = null;

    $.fn.tweetAction = function(options, callback) {
        // Default parameters of the tweet popup:
        options = $.extend({
            url: window.location.href
        }, options);

        return this.click(function(e) {
            if (win) {
                // If a popup window is already shown, do nothing;
                e.preventDefault();
                return;
            }
            var width = 550,
                height = 350,
                top = (window.screen.height - height) / 2,
                left = (window.screen.width - width) / 2;

            var config = [
                'scrollbars=yes', 'resizable=yes', 'toolbar=no', 'location=yes',
                'width=' + width, 'height=' + height, 'left=' + left, 'top=' + top
                ].join(',');

            // Opening a popup window pointing to the twitter intent API:
            win = window.open('http://www.facebook.com/plugins/likebox.php?href=https%3A%2F%2Fwww.facebook.com%2Fekagriyakarya&width&height=62&colorscheme=light&show_faces=false&header=false&stream=false&show_border=false' + $.param(options), 'TweetWindow', config);

            // Checking whether the window is closed every 100 milliseconds.
            (function checkWindow() {

                try {
                    // Opera raises a security exception, so we need to put this code in a try/catch:
                    if (!win || win.closed) {
                        throw "Closed!";
                    } else {
                        setTimeout(checkWindow, 100);
                    }
                }
                catch (e) {
                    // Executing the callback, passed as an argument to the plugin.
                    win = null;
                    callback();
                }

            })();
            e.preventDefault();
        });
    };

})(jQuery);

// Show the Download Button once they Tweet
function showBtn() {
   ...