delphi 2007 Indy 10 Idhttp,Post a website,then RedirectUrl is 'http:',but not wh

I'd like to post a WebSite to loginin

I use a sniffer to catch the http

when I login the website with IE,I find a Post redirecturl that is correct

but when I use idhttp to post the website,I find that,the redirecturl is
'https'

I ask a friend for help,He say there is no question under delphi 7

so,I ask for help!

thanks