-急问。这是什么意思压谢谢

"When I linked up again to asee.org using my wife's Dell with Windows XP and Explorer, and completed the Secure Login, the closed-padlock icon appeared in the Explorer taskbar - which was a relief. BUT as soon as I clicked on the Conference link to reopen my registration and pay, the padlock icon and the https URL vanished - which means that the page with one's credit card number, expiration date and billing address is NOT secure! "

closed-padlock icon 时什么