HTMLFormElement: name property

The HTMLFormElement.name property represents the name of the current <form> element as a string.

If your <form> element contains an element named name then that element overrides the form.name property, so that you can't access it.

const form1name = document.getElementById("form1").name;

if (form1name !== document.form.form1) {
  // Browser doesn't support this form of reference
}