jq 返回上一页事件

<script>
jQuery(document).ready(function ($) { if (window.history && window.history.pushState) { 
$(window).on('popstate', function () { 
var hashLocation = location.hash; 
var hashSplit = hashLocation.split("#!/"); 
var hashName = hashSplit[1]; if (hashName !== '') {
 var hash = window.location.hash; 
 if (hash === '') 
 { 
 alert("希望该网站能提供你帮助！"); } } }); 
window.history.pushState('forward', null, './#forward'); }});

</script>