How to Make Button Work Like Link

How to Make Button Work Like Link:

<div width="100%">
<div align="center">
      <input type="submit" name="submit" value="Back" onclick="return cancel_button();" class="button"></input>
  </div>
</div>

Then in javascript make write:
<script type="text/javascript">
function cancel_button(){
//window.top.location.href = "<?php echo $back_url; ?>";
/* For Out of Iframe */
window.location.href = "<?php echo $back_url; ?>";


}
</script>