use cookies to make single sign on

[david xining]

hello,all:
I want to use response.addCookies() method to add Cookies which I get from a backend system.
and after I execute response.sendRedirect("url of backend system") method ,I can direct go to the backend system without log in.But it seems don't work.
I get two cookies :
one is :TempGuid=F2FA1E7C%2DC452%2D4880%2D81ED%2D3D6790D9A922; expires=Wed, 24-Mar-2004 10:38:40 GMT
other is :ASPSESSIONIDCATQRDCS=JCKFDHDCJHOLNENLCPLPFKPJ
I first create new Cookies like this:
Cookies newc = new Cookies(TempGuid,F2FA1E7C%2DC452%2D4880%2D81ED%2D3D6790D9A922);
Cookies newc2 = new Cookies(ASPSESSIONIDCATQRDCS,JCKFDHDCJHOLNENLCPLPFKPJ);
then I add Cookies to the response:
response.addCookies(newc);
response.addCookies(newc2);
last :
response.sendRedirect("url of backend system");
any one should give me any advice ? thanks in advance !