Tutorial Append Login Credentials to URL

The example here is if you had a form on a website that when submitted, needed to use that information to go to a special URL where the login information was all appeneded to the URL. You could have the form post with method GET, but that is limited to the typical ?variable=foo&variable2=bar format.
HTML Form
Typical form with three bits of information that submits to a file called ftp.php