Cookies from 3rdpartycompany.com will not be sent to mycompany.com. Unless you mean something like 3rdpartysubdomain.mycompany.com which a cookie that is set for the mycompany.com domain. Either you're misinterpreting the situation or describing it incompletely/inaccurately here on the list.
Rob Biedenharn http://agileconsultingllc.com Rob@AgileConsultingLLC.com
What happens is this...you login and are sent to a 3rd party billing company. Therefore, you login at www.mycompany.com which sends you to www.billingcompany.com. At the www.billingcompany.com site they set a cookie...unfortunately, people keep pressing the back arrow.... and then they go forward and of course the cookie is already there and flips out there system.
I would like to say everytime you hit www.mycompany.com to delete the cookies for www.billingcompany.com.... I know they are not available when my browser is set to www.mycompany.com but they are available when www.billingcompany.com is open....so I want to clear them. Any ideas? This is not an easy one...I know that and it may not even be possible.