Mitch,
You need something to keep the form "sticky". You can do this a couple of ways... one if you have the Cookies Toolkit from WebAssist, you could use it to store the entire form in a cookie and then when the body loads, it will fill all values (except password) from the cookie that would have been established.
The other way to do is it with a bit of PHP hand coding. Since when somebody submits a form, it will then get loaded into the POST array with fields of the same name... such as a form element with name "name" become $_POST['name'] so you could check to see if each element is set in the POST array and if it is, you would then populate the original value with the POST value.
Best regards,
Brian