如何用javascript编写for循环

从这段代码中，我在get-emplyee.php页面中编写了select查询，我得到了该页面的答案，之后我返回了上一页（home.php）的数据。从该页面中，我在此标记之前为javascript编写了循环class="col-md-3"我想打开for循环并附加class="Under_Manager"的值

从这段代码中，我可以得到这样的错误SyntaxError:预期的表达式，得到了"｝"

<script type="text/javascript">
   $(document).ready(function(){
       $('.getEmployee').click(function(){
          var emp_id = $(this).attr("rel");
          $.ajax({
             type:'POST',
             url :"get-employee.php",
             data : { emp_id : emp_id},
             success: function(data) {
                 var res=jQuery.parseJSON(data);// convert the json
                 console.log(res);
                 if(res['status']=="success"){
                   var htmlString='';                                 
                   var htmlString = '<section class="content-header"><h1>Employee</h1></section><!-- Main content --><section class="content"><div class="row"><div class="col-xs-12"><div class="box"><div class="row" style="margin:10px">'+$.each( res['data'], function( key, value ) {+'<div class="col-md-3"><!-- Widget: user widget style 1 --><div class="box box-widget widget-user"><!-- Add the bg color to the header using any of the bg-* classes --><div class="widget-user-header" style="background-color: red;color:#fff"><h3 class="widget-user-username">Soundharajan</h3><h5 class="widget-user-desc">Manager</h5></div><div class="widget-user-image"><img class="img-circle" src="../TV/php/upload/unknown-img.jpg" alt="User Avatar"></div><div class="box-footer"><div class="row"><div class="col-sm-6 border-right"><div class="description-block"><h5 class="description-header">9862626427</h5><span class="description-text">Mobile</span></div><!-- /.description-block --></div><!-- /.col --><div class="col-sm-6"><div class="description-block"><h5 class="description-header">BE</h5><span class="description-text">Education</span></div><!-- /.description-block --></div><!-- /.col --></div><!-- /.row --></div><button type="button" data-loading-text="Loading..." class="btn btn-primary btn-block view_employee" style="background-color: red;color:#fff;border-color:red"> View Task </button></div><!-- /.widget-user --></div></div></div></div>'+});+'</div></section><!-- /.section -->'
                       
                   $(".Under_Manager").prepend(htmlString);
                        
                 }else{
                   console.log('erorr');
                 }
            },
            error:function(exception){
               alert('Exeption:'+exception);
            }
        }); 
     });
   });
</script>
    
    
<!--get-employee.php-->
      
      
<?php
session_start();
include('dbconfig.php');
if(empty($_SESSION['email'])){
  header('Location:login.php');
}
$userlevel = $_SESSION['is_user_type'];
$emp_id  = $_POST['emp_id'];
$sql=mysql_query("SELECT * FROM task_employee WHERE emp_underon ='$emp_id'");
$data = array();
while($row=mysql_fetch_assoc($sql)){
	$data[] = $row;
}
$count = sizeof($data);
if($count > 0){ 
    $return=array('status'=>'success','count'=>sizeof($data),'data'=>$data);
	 echo json_encode($return);
}else{
		$return=array('status'=>'error'.mysql_error(),'count'=>sizeof($data),'data'=>$data);
	 echo json_encode($return);
}
?>

  <div class="Under_Manager"></div>