changing shipping/billing address

[brycej2]

Ok when a user needs to change their shipping or billing address, a form is opened for them to them to do so. The file tpl_modules_checkout_new_address.php contains the form that is used in each case and it decides what to do with the data based on whether it is the billing or shipping address they are changing. Well I need a modified form for shipping, but the original form is fine for billing, so I need, based on whether they are changing the billing or shipping address to give them the right form. I looked at some of the "if" statements in tpl_modules_checkout_new_address.php and tried giving them the right form based on this:

if ($_SESSION['billto']) {
   //orignal form
} else if ($_SESSION['shipping']) {
  //modified shipping form
} 

It will give them the modified shipping form at first if they try to change shipping address at the very first and the original form if they try to change billing, but after that if they try to change the shipping address again at any point it gives them the original (billing) form, but the shipping address title and headings...how is this possible? If the shipping headings are still making it there, how would the check on the SESSION see it as billing and give them the original (billing) form? Is there a better logic to use to get them the proper form?


hope I wasn't too confusing trying to explain that...