Ajax is not aborting

var started = false;
      $(document).ready(function () {
      $('#start').click(function () {
      var count = $("#list").val();
      var line = count.split("\n");
      started = true;
      line.forEach(function(value, index) {
          setTimeout(
                  var ajaxCall = $.ajax({
                      url: url,
                      type: 'GET',
                      data: someData,
                      success: function(result) {
                          //some works here
                       }
                  });
                          $('#stop').click(function () {
                          ajaxCall.abort();   //abort Ajax
                          $('#check').attr('disabled', false);
                          $('#stop').attr('disabled', 'disabled');

                      })
              }, 2000 * index);
           });
      });
  });