diff --git a/lib/ldap_login/login.rb b/lib/ldap_login/login.rb
index 4645bf5..efdbe8b 100644
--- a/lib/ldap_login/login.rb
+++ b/lib/ldap_login/login.rb
@@ -10,51 +10,53 @@ module LdapLogin::Login
     _session = {'ad' => []}
     url = '/'
     url_method = 'redirect_to'
-    ldap_hosts.each do |ldap_host|
-      begin
-        ldap = Net::LDAP.new
-        ldap.host = ldap_host
-        ldap.port = 389
-        ldap.auth "#{ldap_user}@asia.edu.tw", ldap_pass
-        if ldap.bind
-          if !user.nil?
-            #filter = Net::LDAP::Filter.eq( "sAMAccountName", ldap_user )
-            #treebase = "ou=Asia Univ,dc=asia,dc=edu,dc=tws"
-            #puts "==LDAP SEARCH START=="
-            #ldap.search( :base => treebase, :filter => filter, :return_result => false ) do |entry|
-            #  puts "DN: #{entry.dn}"
-            #  entry.each do |attribute, values|
-            #    puts "   #{attribute}:"
-            #    values.each do |value|
-            #      puts "      --->#{value}"
-            #    end
-            #  end
-            #end
-            puts "==LDAP SEARCH END=="
-            session[:user_id] = user.id
-            session[:login_referer] = nil
-            if params[:referer_url]
-              url = URI.parse(params[:referer_url]).path
-              url_method = 'redirect_to' 
+    if !ldap_pass.blank?
+      ldap_hosts.each do |ldap_host|
+        begin
+          ldap = Net::LDAP.new
+          ldap.host = ldap_host
+          ldap.port = 389
+          ldap.auth "#{ldap_user}@asia.edu.tw", ldap_pass
+          if ldap.bind
+            if !user.nil?
+              #filter = Net::LDAP::Filter.eq( "sAMAccountName", ldap_user )
+              #treebase = "ou=Asia Univ,dc=asia,dc=edu,dc=tws"
+              #puts "==LDAP SEARCH START=="
+              #ldap.search( :base => treebase, :filter => filter, :return_result => false ) do |entry|
+              #  puts "DN: #{entry.dn}"
+              #  entry.each do |attribute, values|
+              #    puts "   #{attribute}:"
+              #    values.each do |value|
+              #      puts "      --->#{value}"
+              #    end
+              #  end
+              #end
+              puts "==LDAP SEARCH END=="
+              session[:user_id] = user.id
+              session[:login_referer] = nil
+              if params[:referer_url]
+                url = URI.parse(params[:referer_url]).path
+                url_method = 'redirect_to' 
+              else
+                url = admin_dashboards_path
+                url_method = 'redirect_to'
+              end
+              login_flag = true
             else
-              url = admin_dashboards_path
-              url_method = 'redirect_to'
+              error = I18n.t('devise.failure.ldap_pass_but_account_not_in_orbit')
             end
-            login_flag = true
           else
-            error = I18n.t('devise.failure.ldap_pass_but_account_not_in_orbit')
+            error = '驗證失敗，您輸入的使用者名稱或密碼不正確!'
           end
-        else
-          error = '驗證失敗，您輸入的使用者名稱或密碼不正確!'
-        end
-        break
-      rescue => e
-        if !e.class==Net::LDAP::ConnectionError
-          error = '發生不可預知的錯誤'
-          puts ['ldap',error,e]
           break
-        else
-          error = 'Could not connect to AD server.'
+        rescue => e
+          if !e.class==Net::LDAP::ConnectionError
+            error = '發生不可預知的錯誤'
+            puts ['ldap',error,e]
+            break
+          else
+            error = 'Could not connect to AD server.'
+          end
         end
       end
     end