Interstitial page before every external link?

$(document).ready(function() {
   var urlRedirectLandingPage = 'http://somepage.com?redirectUrl=';
   $('a').each(function(a, e) {
     if (e.href.indexOf(window.location.hostname) > -1) {
       return;
     }
     $(e).onclick(function(elem) {
         elem.preventDefault();
         window.location.href = urlRedirectLandingPage + elem.href;
     }
   }
}