def add
    user = User.new
  if request.post?
    begin
        if user.update_attributes(params[:user]) & user.save_with_validation
          flash[:info] = "User Created Successfully"
        else
          flash[:error] = "Can not add a user without selecting a group"
          raise
        end
      rescue
        flash[:error] ="There was an error createing the user"
        raise
      end
    end
     @user = user
     @groups = Group.find(:all)
  end

<% form_for :user, @user, :url => { :action => "add" } do |user_form| %>
  First name: <%= user_form.text_field :first_name %>
  Last name : <%= user_form.text_field :last_name %>
  Email: <%= user_form.text_field :email %>
  Password: <%= user_form.password_field :password %>
  Confirm Password: <%= user_form.password_field :password_confirmation %>
  Groups:
  <% for group in @groups %>
    <%= group.name %> <%= check_box_tag('user[groups]', @groups, -1)%>
  <% end %>
 <%= submit_tag "Login" %>
<% end %>