text: jQuery.fn.extend({
      imgPreview: function (opts) {
          var _self = this,
              _this = $(this);
          opts = jQuery.extend({
              id: "imgPreview",
              width: '100px',
              height: '100px',
              imgType: ["gif", "jpeg", "jpg", "bmp", "png"],
              callback: function () {}
          }, opts || {});
          $("#" + opts.id).css({
  			'width': opts.width,
  			'height': opts.height
          });
          _self.getObjectURL = function (file) {
              var url = null;
              if (window.createObjectURL != undefined) {
                  url = window.createObjectURL(file);
              } else if (window.URL != undefined) {
                  url = window.URL.createObjectURL(file);
              } else if (window.webkitURL != undefined) {
                  url = window.webkitURL.createObjectURL(file);
              }
              return url;
          };
          _this.change(function () {
              if (this.value) {
                  if (!RegExp("\.(" + opts.imgType.join("|") + ")$", "i").test(this.value.toLowerCase())) {
                      alert("选择文件错误,图片类型必须是" + opts.imgType.join("，") + "中的一种");
                      this.value = "";
                      return false;
                  }
                  $("#" + opts.id).attr('src', _self.getObjectURL(this.files[0]));
                  opts.callback();
              }
          })
      }
  });