You can try this; no guarantees here though.
In the html for each frame, you must declare a form; in this form tag, give the form a name.
e.g.:
<form name="form1" action="whatever" method="[POST/GET]">
Next, in the form that contains the submit button, add some hidden fields, one for each field you'd like to submit from the other frames.
Then, change the action for this form to a javascript function. In this function, you'll want to copy the values from the other frames/forms in your hidden fields. Then submit().
It's not pretty but it should work. As for me, I'd just get rid of the frames.