centerDialog.js

      // Ensure that the interstitial is properly centered.
      var $centerDialog = function($dialog) {
        var marginTop = ($dialog.height() + ($($window).height() / 2)) * -1;
        var marginLeft = ($dialog.width() + ($($window).width() / 2)) * -1;

        $dialog.css({
          top: '50%',
          left: '50%',
          margin: marginTop+'px 0 0 -' + marginLeft+'px'
        });
      };

      $centerDialog($cryptoDialog);