Using Flash, WebService and Client Cookies

In a recent project i converted a .NET/Html login function to a Flash 8 login page.
My Flash first used the WebService and PendingCall to cummicate with the .NET webservice.

It all worked fine, except the fact that the login function uses a client cookie for authentication :P
As I found out, if you set a client cookie in a webservice it can't be accesible from the client.

I did not find any standard way to solve this yet, so i threw the webservice in the "thrash" and made a regular aspx page and used the LoadVars object.

If anyone have a smooth example to solve this please let us know =)