Hi all !
According to this MSDN article, to modify an existing subkey in a cookie, you just do this :
Response.Cookies("userInfo")("lastVisit") = DateTime.Now.ToString
Response.Cookies("userInfo").Expires = DateTime.Now.AddDays(1)
The problem is.... it destroys all other subkeys. Actualy, it seems like it deletes the cookie and recreate a new one. So, is there an easy way to modify a subkey in a cookie or do I have to copy all values from the Request cookie inside the Response cookie before changing the Expires date ?