Update not working

I have a page that uses jquery lightboxes to pop up 2 forms. The first is an update form and the second is a multiple insert form. A 'memberID' session value is passed from the previous page.
The upload form pops up on page load and displays the current password that is pulled in from the database using the memberID session variable (this works correctly). The user can then change the password if they wish using the update form (this doesn't work). Once the form is submitted another form pops up and allows the user to insert multiple email addresses and also inserts the memberID session value (this works).

The multiple insert form works fine but the update form doesn't. I thought it might be something to do with the fact that I have both forms on one page and the page isn't being reloaded inbetween form posts. So I created another page with the same code but only added the update form (without the insert form) and it still doesn't work.