$(function() {

  $('#pdf').click(function(){
    var ebRand = Math.random()+'';
    ebRand = ebRand * 1000000;

    $.ajax({
      type: 'GET',
      url: 'HTTP://bs.serving-sys.com/BurstingPipe/ActivityServer.bs?cn=as&ActivityID=127849&rnd=' + ebRand,
      async: false
    });
  });

});