viewport.js

  // -----------
  // Debugger that shows view port size. Helps when making responsive designs.
  // -----------

  function showViewPortSize(display) {
    if(display) {
      var height = jQuery(window).height();
      var width = jQuery(window).width();
      jQuery('body').prepend('<div id="viewportsize" style="z-index:9999;position:fixed;top:40px;left:5px;color:#fff;background:#000;padding:10px">Height: '+height+'<br>Width: '+width+'</div>');
      jQuery(window).resize(function() {
        height = jQuery(window).height();
        width = jQuery(window).width();
        jQuery('#viewportsize').html('Height: '+height+'<br>Width: '+width);
      });
    }
  }

showViewPortSize(true);