Here is an interesting issue. It's about the need to set a cookie across multiple servers. Following the regular approach, such is only applicable if the domain is a sub domain of where the transaction has been initiated. That is done like that in a way to make it secure so no one can set a cookie to another server. However, there are situations where you control multiple domains under the same server, where those domains are not linked together with sub domains, and that you need to set a cookie across all of them.

So far, I was using an approach of forwarding an ID in the URL or transmitting a form with the ID in it to the switched domain. Then, into this new domain, I was simply reading the URL or the form and I was able to read the other domain's cookie.

Now, I would like to really set a cookie across multiple domains on the same server in order to avoid doing such. Is there such a possibility?

I tried today to have a hidden frame to be linked to another URL such as window.location=something but that won't set the cookie on the Web server as security kicks in as this has not been launched by the user but programatically.