TOPIC:

$("#mainPanel").append('<button id="restartBtn">Restart</button>');

$("#restartBtn").button().click(function() {
  // change the variables storing when the activity is complete etc.
  currvalue = undefined;
  correct_answers = 0;
  total = 0;
  labelAnswers = {};
  $("#pageContents").data({ "score": 0, "attempts": 0 });

  // then reset what's on screen
  $("#targetHolder input")
     .val('')
     .attr("readonly", false)
     .addClass("incorrect");

  $("#pageContents").find("#hint").remove();
  $("#feedbackTxt").hide();
});