There is a typo in the document. Windows Explorer 7.x, Item 3b. Says "Leave of" should be "Leave off".
Alternative text: "Type the URL of your LAMS server into the "Address of website to allow" entry, omitting the http:// prefix. For example, type in demo.lamscommunity.org to allow pop-ups from the LAMS demo site."
The same error occurs in the Firefox instructions.