require 'net/ldap'
  def authenticate_login
    username = params[:username]
    password = params[:password]
    ldap = Net::LDAP.new
    ldap.host = '(YOUR LDAP HOST)'
    ldap.port = 389
    ldap.auth "MAINOFFICE\\#{username}", password
    if ldap.bind && password != '' && !password.nil?
      ##Logged in successfully
    end
  end