Develop a web 2.0 style form, needs ajax/js

Please see the included zip file. It shows the GUI of a web form. The form has four different stages. In stage 1 ([login to view URL]) option 1 is checked from the first box and "no" is checked in the second box. In stage 2 ([login to view URL]) option 1 is checked from the first box and "yes" is checked in the second box. In stage 3 ([login to view URL]) option 2 is checked from the first box and "no" is checked in the second box. In stage 4 ([login to view URL]) option 2 is checked from the first box and "yes" is checked in the second box. By default, i.e. when the page shows, stage 1 is selected. The stage selection must be implemented in a way changing the form stage does not require the page to be reloaded. In other words, it needs to be done with JavaScript / AJAX client side scripting. You are not allowed to use Flash or other scripting that requires a browser plugin. The fields must have the following data checks: Field1 must contain a string, no numbers. Field2 must contain a string, no numbers. Field3 must contain a string and at least one number. Field4 must a numeric value of five numbers, counting the leading zeros. E.g. 00100 is a valid input, 100 is not. Field5 must contain a string, no numbers. Field6 must contain a string that looks like a valid email address. Note: It must be possible to use different strings for "text field: lorem ipsum...." in different stages of the form. I.e. it cannot be the same string only moved to the correct place. The web form must work with all the most common browsers. The GUI doesn't have to look as nice as in the design in old browsers.