Http to Https and back data transfer?

[Hazardous]

Hi, I have been asked to change the workings of this website:

http://www.iqtoys.co.nz

pretty much as soon as you get off the main page it enables the SSL
this is an easy change to stop it from doing that and enabling the SSL only when viewing the shopping cart and the order pages etc...
The problem is the shopping cart. At the moment the shopping cart uses cookies.
Will the cookie data remain when switching between http and https protocols?

Do I need to change the shopping cart to use php sessions?

At the moment the site uses php and mysql



Any help would be great, as I don't intend to ruin their business by stuffing up the shopping process. (Which as you all should know is very important for an online E-tail store)

Thanks Again

[gavwvin]

You can set cookies to only be sent over https, but on visiting your site, adding a item to my cart and looking at my cookies it said they were for any type of connection, so it should be available for both connections

[Hazardous]

Thanks a lot, it's always good to get a second opinion