How to shop @ ASOS???

Have been staring at this bag for the longest time:



http://www.asos.com/Asos/Asos-Double-Buckle-Retro-Satchel/Prod/pgeproduct.aspx?iid=1330805&cid=9265&Rf-200=6&sh=0&pge=0&pgesize=20&sort=-1&clr=Mustard


Nope not trying to make a wishlist here and ask anyone out there to buy for me, BUT rather I wanna know how the procedures do purchase from ASOS...CAN ANYBODY HELP ME OUT HERE?


Yes imma bag-whore, I know.