If you know a persons user name how can you find him or his items. how do you look him up

[johnleo16]

If you know someones user name who is also aseller how do you find his items or get in touch with him.

[estreetplazacanada]

You can on the "advanced" beside the search bar.  Then on the left hand side click on advanced search by seller, and you can enter their seller ID.

Try this link, it should take you there: http://www.ebay.ca/sch/ebayadvsearch?_sofindtype=2

Good luck