Disable button on form submission

Question

I have a button that I would like to disable when the form submits to prevent the user submitting multiple times.

I have tried naively disabling the button with java

Answer 1

if the validation is successful, then disable the button. if it's not, then don't.

function validate(form) {
  // perform validation here
  if (isValid) {
    form.mySubmitButton.disabled = true;
    return true;
  } else {
    return false;
  }
}

...