I suggest you read up a little on the HTTP protocol. The application I wrote shows you the HTTP request. It is a post request and the url encoded data is sent in the body of the HTTP request (as shown by the application).

You cannot append the data to the end of a URL and expect it to work. Not only this, the sites you are using have two different forum packages that likely accept login information in a different format, so even if the above were possible, it would probably still fail.