views/signin.erb
<head>
<title>nanoTwitter-signin</title>
</head>
<body data-gr-c-s-loaded="true">
<div class="container">
<h4 class="form-signin-heading"><%= @errorMessage %><br></h4>
<form class="form-signin" action="/signin" method="POST">
<h2 class="form-signin-heading">Please sign in</h2>
<div class="form-group">
<label for="inputEmail">Username</label>
<input type="text" name="username" id="inputEmail" class="form-control" placeholder="Username" required="" autofocus=""></div>
<div class="form-group">
<label for="inputPassword">Password</label>
<input type="password" name="password" id="inputPassword" class="form-control" placeholder="Password" required=""></div>
<button class="btn btn-lg btn-primary btn-block" type="submit">Sign in</button>
</form>
<button class="btn btn-lg btn-primary btn-block" onclick="location='/signup'">Havn't registered? Sign up here!</button>
</div>
</body>