javascript: void ( 
 (function () { 
 var hash = {}; 
 var a = document.evaluate('//input[(@type="radio") and not(@value="0")]//@name', 
     document, 
     null, 
     XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, 
     null); 
 if (a.snapshotLength){ 
  for (var i = 0; i < a.snapshotLength; i++) { 
  if (!(a.snapshotItem(i).value in hash)) 
  hash[a.snapshotItem(i).value] = 0; 
  hash[a.snapshotItem(i).value]++; 
  } 
  for (i in hash) { 
  document.evaluate('//input[(@type="radio") and not(@value="0") and @name="' + i + '"]', 
     document, 
     null, 
     XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, 
     null).snapshotItem(Math.floor(Math.random() * hash[i])).click(); 
  } 
 } 
 var array = new Array(); 
 var as = document.getElementsByTagName("a"); 
 var preName = ""; 
 var change = false; 
 for(var i=0; i < as.length; i++){ 
  if(as[i].getAttribute("rel") != null && as[i].nextSibling.getAttribute("type") == "checkbox"){ 
  var name = as[i].nextSibling.getAttribute("name"); 
  var check = as[i].nextSibling.getAttribute("checked"); 
  if(check == "checked"){ 
   as[i].click(); 
  } 
  if(preName == "" || preName == name){ 
   if(Math.random() * 10 > 5){ 
   as[i].click(); 
   change = true; 
   } 
  } 
  var next = as[i + 1]; 
  if(next.getAttribute("rel") != null && next.nextSibling.getAttribute("type") == "checked" && next.getAttribute("name") != name){ 
   if(!change){ 
   as[i].click(); 
   } 
   change = false; 
  } 
  if(i == as.length - 1 && !change){ 
   as[i].click(); 
  } 
  preName = name; 
  } 
 } 
 var objs = document.getElementsByTagName("textarea"); 
 for (var i = 0; i < objs.length; i++){ 
  objs[i].focus(); 
  objs[i].value = "最好的意见就是没有意见，哈哈哈哈哈哈哈"; 
  objs[i].blur(); 
 } 
 var choose = document.getElementsByTagName("select"); 
 for (var i = 0; i < choose.length; i++) { 
  choose[i].focus(); 
  choose[i].value = "1"; 
  choose[i].blur(); 
 } 
 })()); 
function validate(){return true;} 
var btn = document.getElementById("submit_button"); 
window.setTimeout(btn.click(),2000); 

if (J[0].checked || J[1].checked) { 
 alert('系统检测到非法填写问卷'); 
 window.location.href = window.location.href; 
 return; 
} 

<li style="width:99%;"> 
<a href="javascript:" rel="external nofollow" class="jqCheckbox" rel="q2_2"></a> 
<input style="display:none;" id="q2_2" name="q2" value="2" type="checkbox"> 
<label>选项8</label> 
</li>