Sign in form

new.html.erb

sessions controller action:

def create
    user = User.find_by_email(params[:email])
    if user && user.authenticate(params[:password])
      session[:user_id] = user.id
      redirect_to root_url, :notice => "Successfully signed in."
    else
      flash.now.alert = "Invalid email or password."
      @title = "Sign In"
      render 'new'
    end
  end

this works:

<%= form_tag sessions_path do %>
  <div class="field">
    <%= label_tag :email %>
    <%= text_field_tag :email, params[:email] %>
  </div>
    <div class="field">
    <%= label_tag :password %>
    <%= password_field_tag :password %>
  </div>
  <div class="actions"><%= submit_tag "Log in"%></div>
<% end %>

this doesn't:

<h1>Sign in</h1>

<%= form_for(:session, :url => sessions_path) do |f| %>
  <div class="field">
    <%= f.label :email, "Email:" %><br />
    <%= f.text_field :email %>
  </div>
  <div class="field">
    <%= f.label :password, "Password:" %><br />
    <%= f.password_field :password %>
  </div>
  <div class="actions">
    <%= f.submit "Sign In" %>
  </div>
<% end %>

<p>New user? <%= link_to "Sign up now!", signup_path %></p>