views/signUp.erb
<head>
<title>nanoTwitter</title>
</head>
<div class="container theme-showcase" role="main">
<div class="container">
<form class="form-signin" action="/signup" method="POST" role="form">
<h1 class="form-signin-heading">Welcome to nanoTwitter</h1>
<h2 class="form-signin-heading">Come and register!</h2>
<div class="form-group">
<label for="exampleInputEmail1">Username <em style="color:red"><%= @errorString %></em></label>
<input type="text" name="username" class="form-control" id="exampleInputEmail1" placeholder="Enter Username"></div>
<div class="form-group">
<label for="exampleInputPassword1">Password</label>
<input type="password" name="password" class="form-control" id="exampleInputPassword1" placeholder="Password"></div>
<button class="btn btn-lg btn-primary btn-block" type="submit" >Sign Up Now!</button>
</form>
<button type="submit" class="btn btn-lg btn-primary btn-block" onclick="location='/signin/?'">"Already registered? Login here!"</button>
</div>
</div>