On Load code not executing reliably

On Load code not executing reliably

Let me try again -
I have two fields that supposed to be system generated using the "On Load" functionality. The On Load works the first time the form is used, then stops working. It was working consistently when I wrote the program back in July, and for about 3 months was fine.

Here is the form posted publicly
http://www.freemedads.com/submitad.php

AdCode is supposed to be filled in with an incremented 4 digit #.

TheDate is supposed to be filled in with today's date.

Here is the problem code:

i = "a";
j = "b";
input.TheDate = zoho.currentdate;
x = MaxValueHolder [ID != 0];
input.AdCode = (x.maxval + 1);
x.maxval = (x.maxval + 1);

Thanks!