Javascript-форум - Хотел создать тестирование, но появился "БАГ"

<div id="question_one">
	<center>
		<div class="questions"> Question #1 </div> 
		<div id="answer_1">
						<button class="btn btn-success answers" id="correct_1"> Answer </button> <br>
						<button class="btn btn-success answers" id="uncorrect_1"> Answer </button> <br>
						<button class="btn btn-success answers" id="uncorrect_2"> Answer </button> <br>
						<button class="btn btn-success answers" id="uncorrect_3"> Answer </button> <br>
		</div>
	</center>
</div>

<div style="float: left" id="points">
<span>
Number of question:
<span id="number_of_question"></span>
</span> <br>
<span>
Correctly:
<span id="correctly"></span>
</span> <br>
<span>
Wrong:
<span id="wrong"></span>
</span> <br>
</div>

window.onload = function () {
	var correctly = 0;
	var wrong = 0;
	var question_number = 1;

	jQuery("#question_one").css("display", "none");
	jQuery("#question_two").css("display", "none");
	jQuery("#question_three").css("display", "none");

	var update = setInterval(function() {
		jQuery("#correctly").text(correctly);
		jQuery("#wrong").text(wrong);

		jQuery("#number_of_question").text(question_number);
		return question_number;
	}, 1000/60);

		if (question_number == 1) {
			jQuery("#question_one").css("display", "block");

			jQuery("#correct_1").click(function () {
				correctly++;
				jQuery("#question_one").css("display", "none");
				question_number++;
			});

			jQuery("#uncorrect_1").click(function () {
				wrong++;
				jQuery("#question_one").css("display", "none");
				question_number++;
			}); 

			jQuery("#uncorrect_2").click(function () {
				wrong++;
				jQuery("#question_one").css("display", "none");
				question_number++;
			}); 

			jQuery("#uncorrect_3").click(function () {
				wrong++;
				jQuery("#question_one").css("display", "none");
				question_number++;
			});  
		}
		else if (question_number == 2) {
			console.log(2);
		}

};