I am working on a project with 4 shopping sites which belong to the same company, all sites will be linked to each other.
I am using a cookie to store a customer number and can easily pass this customer number if the user goes from site 1 to site 2 and then once on site 2 store it in the cookie for site 2.
However I would like to be able to write the cookie to the user's machine for the 4 sites when the original cookie is created on site 1, this way if the customer goes directly to let say site 4 without using a link from another site he or she is still recognized as customer number XXXXX

Is this possible?
I am using ASP JavaScript on this sites.
Thanking you for any help,