js code to download a file code example
Example 1: javascript download file
$('a#someID').attr({target: '_blank',
href : 'http://localhost/directory/file.pdf'});
Example 2: js download file from webserver
<iframe id="download_iframe" style="display:none;"></iframe>
<script>
document.getElementById('download_iframe').src = "/example/example.txt";
</script>