Well, your update still leaves me with more questions -- in a lot of ways I think I need to see even more code, but one thing is sticking out right away here:
Can I assume from that you are outputting (or planning on outputting) multiple TR of these inputs? If so, you do know that ID's need to be UNIQUE on the page -- meaning if you have it more than once your code will only ever be able to function on the first row. Looks like you're pulling multiple rows, in which case you should be adding a counter or some other unique per-row identifier to those ID... and the NAME attributes too since if you have more than one row, how are they going to return values at all?
that's also going to make getElementByID VERY difficult to use -- you may end up having to walk the DOM to pull your values instead... which gets very complex; I'd have to see a LOT more of your code to even try to pull that off...
That's the problem with snippets - it's like doing brain surgery through a keyhole without a endoscope.
Often when dealing with making JS work (or CSS for that matter) I'll take and make a flat static HTML file I know is well-formed, and then write the scripting and style to that -- then break up that markup into the PHP. You might want to do that just to remove PHP from the equation so you are certain where to lay the blame.
Also, this is 2014, not 2006, you REALLY shouldn't be using mysql_ anymore, hence the giant red warning boxes in the manual.
... and I'd also find some way to make sure acctNo is stored server side in relation to the form instead of client-side; since it would be far too easy to BS someone else's account number from the client-side value. Really that's why it's NOT a good idea to let people edit account values from a listing and instead have one account per edit page. You can HAVE a listing, but to edit them, give them their own dialog.