The e-commerce site allows users to have more than one basket at a time. Addition of items and checkout is performed against the current basket.
Quick link for current basket's page: 
Click the basket name in the banner of the site.
To select your current basket:
ˇ Access My Baskets -> Current basket from the top menu option
ˇ From the basket name, select the change basket. Highlight the basket in question. This list is populated by "most recent used"
ˇ Select My Baskets -> All baskets from the top menu option. Click on the basket circle checkbox next to the basket
For more information on multiple baskets and multiple shopping groups, see Shared Shopping.