js获取GridView中CheckBox的选中状态

<script language="javascript">
    function show() 
    {
         var ele = event.srcElement;
         if(ele.tagName == "INPUT" && ele.type == "checkbox")
         {
            var text = ele.parentElement.title;
            if(ele.checked == true)
            {
                alert(text + "已被勾选"); 
            }
            else
            {
                alert(text + "已取消勾选"); 
            }
         }

    }
    </script>

/*============================GriView列表项绑定事件==========================*/

 protected void gvListInfo_RowDataBound(object sender, GridViewRowEventArgs e)
    {
           CheckBox chk = (CheckBox)e.Row.FindControl("x_chkID");
           chk.Attributes["OnClick"] = "javascript:show();";
    }