添加收藏夹，只运行一次的javascript代码

function get_cookie(Name)

{

var search = Name + "="

var returnvalue = "";

if (document.cookie.length > 0)

{

    var offset = document.cookie.indexOf(search)

    if (offset != -1)

    {

        offset += search.length

        end = document.cookie.indexOf(";", offset);

    if (end == -1)

        end = document.cookie.length;

       

    returnvalue=unescape(document.cookie.substring(offset, end))

    }

}

return returnvalue;

}

function WindowClose()

{

    var s = get_cookie('bookmarkit')

    alert(s)

    if (s=='')

    {

        if( confirm("感谢您访问本网站。您愿意收藏天气在线吗？"))

        {

            document.cookie="bookmarkit=yes"

            JSAddFavorite()

         }

     }

}