<html>
<body>
<form name="form1">
<input type="radio" name=button1>Box 1
<br>
<input type="radio" name=button2>Box 2
<br><br>
<input type="button" value="Get Form Name"
onClick='console.log("The form name is: " + document.form1.button1.form.name)'>
</form>
</body>
</html>