diff --git a/ident_switch.php b/ident_switch.php
index f4e865b..2beadd0 100644
--- a/ident_switch.php
+++ b/ident_switch.php
@@ -182,6 +182,8 @@ class ident_switch extends rcube_plugin
 	{
 		$rc = rcmail::get_instance();
 
+		$this->add_texts('localization');
+
 		// Check field values
 		$noErrors = false;
 
@@ -201,7 +203,7 @@ class ident_switch extends rcube_plugin
 				else
 				{
 					if ($fPort && ($fPort <= 0 || $fPort > 65535))
-						$rc->output->show_message('err.port.num', 'error');
+						$rc->output->show_message('err.port.range', 'error');
 					else
 					{
 						$fUser = self::ntrim(get_input_value('_ident_switch_form_username', RCUBE_INPUT_POST));
@@ -210,7 +212,7 @@ class ident_switch extends rcube_plugin
 						else
 						{
 							if (!$fUser)
-								$rc->output->show_message('err.user.empty', 'error');
+								$rc->output->show_message('ident_switch.err.user.empty', 'error');
 							else
 							{
 								$fDelim = self::ntrim(get_input_value('_ident_switch_form_delimiter', RCUBE_INPUT_POST));
diff --git a/localization/en_US.inc b/localization/en_US.inc
index d20ad63..07b082d 100644
--- a/localization/en_US.inc
+++ b/localization/en_US.inc
@@ -30,3 +30,24 @@ $labels['form.password'] = 'Password';
 
 // Folder hierarchy delimiter
 $labels['form.delimiter'] = 'Folder hierarchy delimiter';
+
+// \'Username\' field in IMAP section cannot be empty.
+$labels['err.user.empty'] = '\'Username\' field in IMAP section cannot be empty.';
+
+// Value in \'Label\' field of IMAP section is too long (32 chars max).
+$labels['err.label.long'] = 'Value in \'Label\' field of IMAP section is too long (32 chars max).';
+
+// Value in \'Server host name\' field of IMAP section is too long (64 chars max).
+$labels['err.host.long'] = 'Value in \'Server host name\' field of IMAP section is too long (64 chars max).';
+
+// Value in \'Username\' field of IMAP section is too long (64 chars max).
+$labels['err.user.long'] = 'Value in \'Username\' field of IMAP section is too long (64 chars max).';
+
+// Value in \'Folder hierarchy delimiter\' field of IMAP section is too long (1 char max).
+$labels['err.delim.long'] = 'Value in \'Folder hierarchy delimiter\' field of IMAP section is too long (1 char max).';
+
+// Value in \'Port\' field of IMAP section must be a number.
+$labels['err.port.num'] = 'Value in \'Port\' field of IMAP section must be a number.';
+
+// Value in \'Port\' field of IMAP section must be between 1 and 65535.
+$labels['err.port.rtange'] = 'Value in \'Port\' field of IMAP section must be between 1 and 65535.';