No... no hidden form needed.
The second insert would just use:
$WA_fieldValuesStr = "".((isset($_SESSION['NewUserID']))?$_SESSION['NewUserID']:"")
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.