javascript submit ทีนี้ผมจะให้มันย้อนกลับมาด้วย history.back(); มันกลับไม่ได้ครับ

<script type="text/javascript">
	function submitform(value) {
	
		if (value == 1) {
			document.form1.txt2.value = value;	
			document.form1.action="Untitled-3.php";
			
		}else if(value == 2){
			document.form1.txt2.value = value;
		    document.form1.action="Untitled-3.php";
		}
	}

</script>

<form id="form1" name="form1" method="post" action="">
  <label>
  <input type="text" name="txt" id="txt" />
  </label>
  <label>
  <input type="submit" name="button" id="button" value="Submit" onclick="submitform(1);" />
  </label>
  <label>
  <input type="submit" name="button2" id="button2" value="Submit" onclick="submitform(2);" />
  </label>
  
  <input type="hidden" name="txt2" id="txt2" />
</form>