mailto: URLs in JavaScript

email.js

// http://xion.io/post/code/js-mailto-urls.html

function getMailtoUrl(to, subject, body) {
  var args = [];
    if (typeof subject !== 'undefined') {
        args.push('subject=' + encodeURIComponent(subject));
    }
    if (typeof body !== 'undefined') {
        args.push('body=' + encodeURIComponent(body))
    }

    var url = 'mailto:' + encodeURIComponent(to);
    if (args.length > 0) {
        url += '?' + args.join('&');
    }
    return url;
}