Prevent multiple submits when clicked a submit button

form.html

<form action='/'>
  <button class="prevent-multiple-submit" type="submit">Create</button>
</form>

prevent_multiple_submit.js

function disableButton(event) {
  event.target.setAttribute('disabled', 'disabled');
  event.target.form.submit();
}

var preventButtons = document.getElementsByClassName('prevent-multiple-submit');
var i;

for (i = 0; i < preventButtons.length; i++) { 
  preventButtons[i].addEventListener('click', disableButton);
}