When you have your eBay auction showing on your computer screen (you are at that web page), click on the address that is in the place next to "Address" at the top of your browser. That will highlight that info. Hold down the control key on your keyboard and hit the letter c. Then you come here, and toward the bottom of the "Post Response" area, there is the Optional Link URL box. Click in it to get a curser there. Remove what is already there (http://) by hitting the backspace button until the box is empty. Now, hold down the control key on your keyboard again, but this time, hit the letter v. That will put the link URL into the box.

In the Optional Link Title box, name it what ever you want.

Bob