function deleteUrl(){
   $("body").on("click",".img-wrap .mask span",function(event){
    event.stopPropagation();
          
    var qs=$('#file_upload-queue>div');//所有的队列
    var id=qs.eq(2).attr('id');//得到第三个队列的id
    $('#uploadTowedAccredit').uploadify('cancel',id);//这样就行了，会自动重置队列数量和删除dom对象，不能直接qs.eq(2).remove()，无效
      
    /*
    if(!window.confirm("您确定删除附件？")){
      return;
    }
    var imgUrl=$(this).parents(".img-wrap").find("img").attr("src");
    deleteImage(imgUrl);
    $(this).parents(".img-wrap").remove();
    */
  });
};

<li class="blockli clearfix" style="padding-bottom: 5px;">
  <span class="left-name"><em class="red-star">*</em>拖机授权委托书：</span>
  <div class="upload-wrap" style="width:100px;">
    <input type="file" name="uploadTowedAccredit" id="uploadTowedAccredit" class="filetext"/>
  </div>
  <span id="uploadTowedAccreditLinkTip" class="warn-tips"><em></em>请上传附件，最多上传${towedAccreditPicMax} 张</span>
  <div id="towedAccreditDiv" class="up-img-list clearfix"></div>
</li>

// 上传拖机授权委托书
function uploadTowedAccreditInit(){
   $("#uploadTowedAccredit").uploadify({
    'hideButton':'true',
    'preventCaching' : 'true',
    'checkExisting':'true',
    'swf': SWF, 
    'uploader':uploadImg,
    'debug':false,
    'multi': true,
    'method': 'post',
    'preventCaching' : true,
    'removeCompleted' : true,
    'removeTimeout' : 10,
    'requeueErrors' : true,
    'successTimeout' : 30,
    'uploadLimit' : ${towedAccreditPicMax},
     
    'fileObjName' : 'Filedata',
    //单张图片最大限制
    'fileSizeLimit' : '1024KB',
    'fileTypeDesc' : 'Image Files',
    //仅限上传jpg格式图片
    'fileTypeExts' : '*.jpg;*.png',
    'height': 24,
    'width':73,
    'buttonText' : '上传附件',
    'auto': true,
    'buttonClass':'uploada btn-fff-24',
   
    'onSWFReady' : function() {
    },
     
    'onInit':function(){
      // $("#file_upload-button").css("width","100");
     },
         
    //选择图片完成
    'onSelect' : function() {
 
    },
     
    //取消上传
    'onCancel' : function(file) {
    },
    'onCheck': function(event,data,key) {
    },
    //开始上传
    'onUploadStart' : function(file) {
      $('.uploadify-queue').html('');
    },
     
    //上传过程中
    'onUploadProgress' : function(file, bytesUploaded, bytesTotal, totalBytesUploaded, totalBytesTotal) {
      $('.uploadify-queue').html('');
      $("#uploadTowedAccreditLinkTip").html('<em></em>上传中...');
    },
     
    //上传完成
    'onUploadComplete' : function(file) {
        $('.uploadify-queue').html('');
        $("#uploadTowedAccreditLinkTip").html('<em></em>上传成功，待提交');
    },
     
    //上传成功
    'onUploadSuccess' : function(file, data, response) {
      var obj = eval('(' + data + ')');
        var result=obj.result;
        if(result=="true"){
          var filename=obj.filename;
          $('.uploadify-queue').html('');
          $('#towedAccreditDiv').append("<div class='img-wrap'><img width='112' height='84' alt='' src='"+filename+"'><div class='mask'><em></em><span></span></div></div>");
        }
    },
     
    //上传失败 //附件格式不正确，请上传JPG、BMP、PNG格式文件，大小不超过3MB
    'onUploadError' : function(file, errorCode, errorMsg, errorString) {
      switch(errorCode) {
        case -100:
          alert("上传的文件数量已经超出系统限制的"+$('#uploadTowedAccredit').uploadify('settings','queueSizeLimit')+"个文件！");
          break;
        case -110:
          alert("文件 ["+file.name+"] 大小超出系统限制的"+$('#uploadTowedAccredit').uploadify('settings','fileSizeLimit')+"大小！");
          break;
        case -120:
          alert("文件 ["+file.name+"] 大小异常！");
          break;
        case -130:
          alert("文件 ["+file.name+"] 类型不正确！");
          break;
      }
    },
    //上传失败 //附件格式不正确，请上传JPG、BMP、PNG格式文件，大小不超过3MB
    'onSelectError' : function(file, errorCode, errorMsg) { 
      var msgText = "上传失败\n"; 
      switch (errorCode) { 
        case SWFUpload.QUEUE_ERROR.QUEUE_LIMIT_EXCEEDED: 
          var towedAccreditDivLen = $("#towedAccreditDiv").children().length;
          msgText += "每次最多上传 " + $('#uploadTowedAccredit').uploadify('settings','uploadLimit') + "个文件"; 
          break; 
        case SWFUpload.QUEUE_ERROR.FILE_EXCEEDS_SIZE_LIMIT: 
          msgText += "文件大小超过限制( " + $('#uploadTowedAccredit').uploadify('settings','fileSizeLimit') + " )"; 
          break; 
        case SWFUpload.QUEUE_ERROR.ZERO_BYTE_FILE: 
          msgText += "文件大小为0"; 
          break; 
        case SWFUpload.QUEUE_ERROR.INVALID_FILETYPE: 
          msgText += "文件格式不正确，仅限 " + $('#uploadTowedAccredit').uploadify('settings','fileTypeExts'); 
          break; 
        default: 
          msgText += "错误代码：" + errorCode + "\n" + errorMsg; 
      }
      alert(msgText);
    }
  });
   
  //判断用户是否有安装flash
 var obj = $("#uploadTowedAccredit").children().eq(0);
 if(obj.attr('type')!= "application/x-shockwave-flash"){
    alert('系统检测到您的浏览器没有安装flash插件，为了你能够正常上传图片，建议你安装flash');
    return;
  }
   
  $("#uploadTowedAccredit").css("float","left");
};