#CONTROLLER
def update
    @user = User.find(params[:id])

    if @user.update_attributes(params[:user])
      flash[:notice] = 'User was successfully updated.'
      redirect_to @user
    else
      @persons = Person.find(:all)
      render :action => 'edit'
    end
end


def edit
    @user = User.find(params[:id])
    @persons = Person.find(:all)
end

#VIEW
<% form_for(@user) do |f| %>
<table>
    <tr>
        <td>Username:</td>
        <td><%= f.text_field :login -%></td>
    </tr>
    <tr>
        <td>Password:</td>
        <td><%= f.password_field :password -%></td>
    </tr>
    <tr>
        <td>Password again:</td>
        <td><%= f.password_field :password_confirmation -%></td>
    </tr>
    <tr>
        <td>Email:</td>
        <td><%= f.text_field :email -%></td>
    </tr>
    <tr>
        <td>Person:</td>
        <td><%= f.collection_select(:person_id, @persons, :id, :first_name) -%></td>
    </tr>
</table>
<% end %>