_form.html.erb

<%= form_for(@user) do |f| %>
  <%= f.label(:name) %>
  <%= f.text_field(:name) %>
  <%= f.submit %>
<% end -%>

edit.html.erb

<%= render(:partial => 'form') %>

new.html.erb

<%= render(:partial => 'form') %>

users_controller.rb

class UsersController < ApplicationController
  def index
    @users = User.find(:all)
    
    respond_to do |format|
      format.html # index.html.erb
      format.xml  { render(:xml  => @users) }
      format.json { render(:json => @users) }
    end
  end

  def edit
    @user = User.find(params[:id])
  
    respond_to do |format|
      format.html # edit.html.erb
    end
  end

  def update
    @user = User.find(params[:id])
    
    respond_to do |format|
      if @user.update_attributes(params[:user])
        format.html { redirect_to(users_path()) }
      else
        format.html { render(:action => 'edit') }
      end
    end
  end

  def new
    @user = User.new(params[:user])

    respond_to do |format|
      format.html # new.html.erb
    end
  end

  def create
    @user = User.new(params[:user])

    respond_to do |format|
      if @user.save
        flash[:notice] = "Successfully created user."
        format.html { redirect_to(user_path(@user)) }
      else
        flash[:error] = "Unable to create the user."
        format.html { render(:action => 'new') }
      end
    end
  end

  def destroy
    @user = User.find(params[:id])
    
    respond_to do |format|
      if @user.destroy
        flash[:notice] = "Successfully removed the user."
        format.html { redirect_to(users_path()) }
      else
        flash[:error] = "Unable to remove the user."
        format.html { redirect_to(users_path()) }
      end
    end
  end
end