The form property of the Hidden object is used to reference the form containing the Hidden object.
<html>
<head>
<title> Using the form property of the Hidden object</title>
</head>
<body>
<form name="form1">
Form name:<input type="hidden" name="hide1" value="Test">
<P>
<input type="button" value="Form Name"
onClick="this.form.hide1.value=this.form.name">
</form>
</body>
</html>