Do not use submit to name a submit button
Given a form element, we often call the
`submit()` method to submit the form after validating its fields.
If the submit button of the form has either
`id="submit"` attribute, then
`formEle.submit` will return the submit button instance.
As a result,
`formEle.submit()` throws an exception because it's not an actual function anymore.
We can face the similar issue when using special properties of form such as
<button type="submit" name="submit">Submit</button>
<button type="submit" id="submit">Submit</button>
<button type="submit" name="submitButton">Submit</button>