如何实现php+Ajax无刷新上传图片功能？

<!--图片上传begin-->
<script type="text/javascript" src="/js/jquery.form.js"></script>
<script type="text/javascript" src="/js/uploadImg.js"></script>
<link href="/css/uploadImg.css" rel="stylesheet" type="text/css" />
<!--图片上传end-->

<div class="upimg">
<input name="icon" type="text" class="imgsrc" value="<!--{$contents.icon}-->" />
<div class="showimg">
<!--{if $contents.icon}-->
<img src="<!--{$contents.icon}-->" height="120px">
<!--{/if}-->
</div>
<div class="btn" style="height:20px;">
 <span>添加图片</span>
 <input class="fileupload" type="file" name="pic[]">
</div>
</div>

/*图片上传*/
$(".fileupload").wrap("<form action='/bookstore/book/uploadpic' method='post' enctype='multipart/form-data'></form>"); //函数处理

jQuery(function ($) {
 $(".fileupload").change(function(){ //选择文件
  if ('' === $(this).val()) return;
  var upimg = $(this).parent().parent().parent();
  var showimg = upimg.find('.showimg');
  var btn = upimg.find('.btn span');
  var imgsrc = upimg.find('.imgsrc');
  $(this).parent().ajaxSubmit({
   //dataType: 'json', //数据格式为json
   beforeSend: function() { //开始上传
    showimg.empty(); //清空显示的图片
    imgsrc.val("");
    btn.html("上传中..."); //上传按钮显示上传中
   },
   uploadProgress: function(event, position, total, percentComplete) {
   },
   success: function(data) { //成功
    //获得后台返回的json数据，显示文件名，大小，以及删除按钮
    var img = data;
    //显示上传后的图片
    imgsrc.val("");
    imgsrc.val(img);
    showimg.html("<img width='120' height='120' src='"+img+"'>");
    btn.html("上传成功"); //上传按钮还原
   },
   error:function(xhr){ //上传失败
    btn.html("上传失败");
   }
  });
 });
});

public function uploadpicAction(){ //图片上传和显示
  $data = "";
  $src = $this->uploadFiles2($imgpath = "/upload/book" ,$filesname = "pic");
  isset($src[0]['src']) && $src[0]['src'] ? $data = $this->concaturl($src[0]['src']) : null;
  echo $data;
}