There are some client side validations that are occurring that are preventing the form from submitting. The problem seems to be related to the fact that you started with a login form, in the login form all of the elements are required. When I disabled the onBlur code to hide the errors I was able to see the errors. Look at any of the onblur events on the page and remove them, then uncheck that box and try to submit the form, you will see a validation message.
It might be best to start with an all new blank form rather than a login form. You should be able to use this page if you remove all of the validations that are on the page. There are spry validations and some server validations that are used via js. If you remove the include lines for the js files for the validation it should let the form submit regardless of the selections that are made.