Disable/Enable Submit Button until all forms have been filled

Question

I want my form submit button to be disabled/enabled depending on if the form is completely filled.

When the inputs are filled, the disabled button changes to enabled

Answer 1

Just use

document.getElementById('submitbutton').disabled = !cansubmit;

instead of the the if-clause that works only one-way.

Also, for the users who have JS disabled, I'd suggest to set the initial disabled by JS only. To do so, just move the script behind the

and call checkform(); once.