>>I didn't the VALUE default in the checkbox field so the javascript was always using on as the value. After having initialized VALUE=0, the javascript is now using 1 or 0 as the value.
>
>Well, I thought I had first but here's the final result.
>
>To read the value of a checkbox, I have to do document.myform.checkboxfieldname.checked. This will return true or false.

you could have checked the script on my page - it does client side validation of the form there :)

Arnon