ok, well from my understanding you want to set the value of hidden1, hidden2 depending on which submit button is pressed. you already have the onclick event, so inside the event you want to execute...

you don't need to insert any hidden fields as such, just set the value. if this is to be filled when you submit the form, then make use of the onclick event and set the element (your input field)...

what makes you think there is such a thing as document.fontFamily?
as I said, make sure you are using up-to-date and correct properties.

well since background works, why not use the same location.href? You are also making use of deprecated code, you might want to rethink how you are changing the properties.

I think you have broken your own rule already since asp is server-side. Anyway, what you probably want to do is look at AJAX.

Watch your blocks as I think you are missing a few { }.

I would do it slightly different to you, but this is how I would do it:

function confirmSubmit() {
var acc =...

move you window redirecting code to a javascript function. Make your onclick call a function to validate the checkbox (again, in javascript), and then if the checkbox is checked you can then...

Have you tried:

window.location = "???.html";