Javascript change attribute

script yang saya buat sudah berhasil 95%, kenapa?

ini java:

 function hide(){
	document.getElementById('regisform').style.display = 'none';
	document.getElementById('formlogin').style.display = '';
	document.getElementById('btn-login1').style.display = 'none';
	document.getElementById('btn-login2').style.display = 'block';
	document.getElementById('change').style.display = 'none';
	document.getElementById('change1').style.display = 'block';
	document.getElementById('terms').style.display = 'none';
}

function show(){
	document.getElementById('regisform').style.display = '';
	document.getElementById('formlogin').style.display = 'none';
	document.getElementById('btn-login1').style.display = 'block';
	document.getElementById('btn-login2').style.display = 'none';
	document.getElementById('change').style.display = '';
	document.getElementById('change1').style.display = 'none';
	document.getElementById('terms').style.display = 'none';
}

function termShow(){
	document.getElementById('regisform').style.display = 'none';
	document.getElementById('formlogin').style.display = 'none';
	document.getElementById('btn-login1').style.display = 'none';
	document.getElementById('btn-login2').style.display = 'none';
	document.getElementById('change').style.display = 'block';
	document.getElementById('change1').style.display = 'none';
	document.getElementById('terms').style.display = 'block';
}

ini index nya

<div class="login-square">
	<div class="container">
		<div class="login-1">
			<h1> Masuk </h1>
			<hr>
		</div>

		<div class="login-2">
			<p> Sign with your account </p>
			<p> Or Register Only </p>
		</div>

		<div class="login-4">
			<p><a id="change" onclick="hide();"> Already have account? </a></p>

			<p><a id="change1" onclick="show();"> Register? </a></p>
		</div>

<div class="clearfix"></div>

		<form action="" method="POST" name="formlogin">
			<div class="login-3" id="login-input">
				<div class="user">
					<div class="label-user">
						<img class="img-responsive" src="assets/profile.png">
					</div>

					<div class="input-user">
						<input type="text" name="user" id="user" class="form-control" autofocus placeholder=" Username">
					</div>
				</div>

				<div class="pass">
					<div class="label-pass">
						<img class="img-responsive" src="assets/unlock.png">
					</div>

					<div class="input-pass">
						<input type="password" name="pass" id="pass" class="form-control" placeholder=" *******">
					</div>
				</div>
			</div>

			<div class="login-8" id="btn-login2">
				<button type="submit"> Login </button>
			</div>
		</form>

			<div class="terms" id="terms">
				<p> Jika anda mempunyai akun, silahkan login
				dengan memasukkan <i>User</i> dan <i>Password </i> yang benar. Tetapi jika anda tidak mempunyai akun sama sekali, silahkan <i>Register</i> agar anda dapat menikmati <i>Fitur</i> yang menarik dari web ini. </p>
			</div>


		<form action="<?php echo $editFormAction; ?>" method="POST" name="regisform" id="regisform">
			<div class="login-5" id="register-input">
				<div class="user">
					<div class="label-user">
						<img class="img-responsive" src="assets/profile.png">
					</div>

					<div class="input-user">
						<input type="text" name="regis-user" id="regis-user" class="form-control" autofocus placeholder=" Username">
					</div>
				</div>

				<div class="pass">
					<div class="label-pass">
						<img class="img-responsive" src="assets/unlock.png">
					</div>

					<div class="input-pass">
						<input type="password" name="regis-pass" id="regis-pass" class="form-control" placeholder=" *******">
					</div>
				</div>

				<div class="key">
					<div class="label-key">
						<img class="img-responsive" src="assets/tag.png">
					</div>

					<div class="input-key">
						<input type="text" name="regis-key" id="regis-key" class="form-control" placeholder=" Nama">
					</div>
				</div>
			</div>


			<div class="login-6" id="btn-login1">
				<button type="submit"> Sign Up </button>
			</div>
			<input type="hidden" name="MM_insert" value="regisform">
		</form>

		<div class="login-7">
			<p onclick="termShow();"> Terms of Services | Privacy Policy </p>
		</div>

	</div>
</div>

<script type="text/javascript" src="js/login.js"></script>

</html>

masalahnya, ketika saya klik Terms, dan mengklik Already account, isinya akan muncul, tetapi setelah itu saya mengklik register dan walhasil isi tidak terlihat. mohon bantuan :D