1.在www.a.com下放文件set_cookie.asp

内容如下：

<%Response.AddHeader "P3P", "CP=CAO PSA OUR"

'Response.AddHeader "P3P", "CP=CURa ADMa DEVa PSAo PSDo OUR BUS UNI PUR INT DEM STA PRE COM NAV OTC NOI DSP COR"
cookie=Request.Cookies("www_a_com")
if cookie="" then
Dim Imgrandom
Randomize
Imgrandom = Int(79999999999 * Rnd + 20000000000)
t=replace(now(),"-","")
t=replace(t," ","")
t=replace(t,":","")
t=replace(t,"/","")
Response.Cookies("www_a_com").Domain = ".a.com"
Response.Cookies("www_a_com").Path = "/"
Response.Cookies("www_a_com")= t&Imgrandom
Response.Cookies("www_a_com").Expires=Date+365
'response.write request.cookies("www_a_com")
end if
%>
document.write("<%=cookie%>");

2.在www.b.com下放文件get_cookie.asp,内容如下：

<script src="http://stat.adjyc.com/set_cookie.asp"></script> 

打开浏览器，输入www.a.com/set_cookie.asp得到值document.write("201012614292384859328269")

输入www.b.com/get_cookie.asp得到值201012614292384859328269，

说明跨域成功，b.com可以获得a.com的cookie.

3.如果set_cookie.asp去掉Response.AddHeader "P3P", "CP=CAO PSA OUR"，在IE6上，输入www.a.com/set_cookie.asp得到值为空，IE7和8都可以得到值。

4.都是IE内核的得到的cookie值相同，firefox,sarfri等不同浏览器的cookie值不同。