diff --git a/common.php b/common.php
index 3b7d91c3..627ea33f 100644
--- a/common.php
+++ b/common.php
@@ -16,6 +16,9 @@
  * All pages should include this file - which itself sets up the necessary
  * environment and ensures other functions are loaded.
  */
+
+define('POSTFIXADMIN', 1); # checked in included files
+
 $incpath = dirname(__FILE__);
 (ini_get('magic_quotes_gpc') ? ini_set('magic_quotes_runtime', '0') : '1');
 (ini_get('magic_quotes_gpc') ? ini_set('magic_quotes_sybase', '0') : '1');
diff --git a/templates/admin_create-admin.php b/templates/admin_create-admin.php
index ebadebbd..12386da6 100644
--- a/templates/admin_create-admin.php
+++ b/templates/admin_create-admin.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="create_admin" method="post">
 <table>
diff --git a/templates/admin_create-domain.php b/templates/admin_create-domain.php
index cda06a39..9e753509 100644
--- a/templates/admin_create-domain.php
+++ b/templates/admin_create-domain.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="create_domain" method="post">
 <table>
diff --git a/templates/admin_edit-admin.php b/templates/admin_edit-admin.php
index 992601ce..5cfabd96 100644
--- a/templates/admin_edit-admin.php
+++ b/templates/admin_edit-admin.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="alias" method="post">
 <table>
diff --git a/templates/admin_edit-domain.php b/templates/admin_edit-domain.php
index db5267ef..05b3aff1 100644
--- a/templates/admin_edit-domain.php
+++ b/templates/admin_edit-domain.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="edit_domain" method="post">
 <table>
diff --git a/templates/admin_list-admin.php b/templates/admin_list-admin.php
index 755c163b..39198fd1 100644
--- a/templates/admin_list-admin.php
+++ b/templates/admin_list-admin.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <?php 
 if (sizeof ($list_admins) > 0)
 {
diff --git a/templates/admin_list-domain.php b/templates/admin_list-domain.php
index f7b1c57c..db60aea7 100644
--- a/templates/admin_list-domain.php
+++ b/templates/admin_list-domain.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="overview">
 <form name="overview" method="post">
 <select name="fUsername" onChange="this.form.submit();">
diff --git a/templates/admin_search.php b/templates/admin_search.php
index 6081410b..6633e820 100644
--- a/templates/admin_search.php
+++ b/templates/admin_search.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <?php
 require(dirname(__FILE__) . '/search.tpl');
 
diff --git a/templates/broadcast-message.php b/templates/broadcast-message.php
index c2865378..a1b02193 100644
--- a/templates/broadcast-message.php
+++ b/templates/broadcast-message.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="broadcast-message" method="post">
 <table>
diff --git a/templates/create-alias.php b/templates/create-alias.php
index 6682b136..0f29d9e9 100644
--- a/templates/create-alias.php
+++ b/templates/create-alias.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="alias" method="post">
 <table>
diff --git a/templates/create-mailbox.php b/templates/create-mailbox.php
index 0105cb72..ea208297 100644
--- a/templates/create-mailbox.php
+++ b/templates/create-mailbox.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="mailbox" method="post">
 <table>
diff --git a/templates/edit-alias.php b/templates/edit-alias.php
index 8de6a5a6..6c5376b8 100644
--- a/templates/edit-alias.php
+++ b/templates/edit-alias.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="alias" method="post">
 <table>
diff --git a/templates/edit-mailbox.php b/templates/edit-mailbox.php
index 4394f6a1..8ed3a166 100644
--- a/templates/edit-mailbox.php
+++ b/templates/edit-mailbox.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="mailbox" method="post">
 <table>
diff --git a/templates/edit-vacation.php b/templates/edit-vacation.php
index 8a9fe214..3fd349a7 100644
--- a/templates/edit-vacation.php
+++ b/templates/edit-vacation.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <script type="text/javascript">
 function newLocation()
 {
diff --git a/templates/fetchmail.php b/templates/fetchmail.php
index a320d7e0..03b7bcde 100644
--- a/templates/fetchmail.php
+++ b/templates/fetchmail.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <?php 
 
 $headers=array();
diff --git a/templates/footer.php b/templates/footer.php
index d7243186..cbea8794 100644
--- a/templates/footer.php
+++ b/templates/footer.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="footer">
 <a target="_blank" href="http://postfixadmin.com/">Postfix Admin <?php print $version; ?></a>
 &nbsp;&nbsp;&nbsp;|&nbsp;&nbsp;&nbsp;
diff --git a/templates/header.php b/templates/header.php
index 46ffffa8..31b7e946 100644
--- a/templates/header.php
+++ b/templates/header.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <?php
 @header ("Expires: Sun, 16 Mar 2003 05:00:00 GMT");
 @header ("Last-Modified: " . gmdate ("D, d M Y H:i:s") . " GMT");
diff --git a/templates/index.php b/templates/index.php
index b1321bbb..3d46ebd8 100644
--- a/templates/index.php
+++ b/templates/index.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <?php
 //
 // Postfix Admin  
diff --git a/templates/list-virtual.php b/templates/list-virtual.php
index d6744e22..5cd0b127 100644
--- a/templates/list-virtual.php
+++ b/templates/list-virtual.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="overview">
 <form name="overview" method="post">
 <select name="fDomain" onChange="this.form.submit();">
diff --git a/templates/login.php b/templates/login.php
index 6a7a1991..1cc8a5ec 100644
--- a/templates/login.php
+++ b/templates/login.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="login">
 <form name="login" method="post">
 <table id="login_table" cellspacing="10">
diff --git a/templates/main.php b/templates/main.php
index 8eb05da4..3ab97dff 100644
--- a/templates/main.php
+++ b/templates/main.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="main_menu">
 <table>
    <tr>
diff --git a/templates/menu.php b/templates/menu.php
index b40b7963..df37276e 100644
--- a/templates/menu.php
+++ b/templates/menu.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <?php
 function _menulink ($href, $title, $submenu = "") {
    if ($submenu != "") $submenu = "<ul><li><a target='_top' href='$href'>$title</a>$submenu</li></ul>";
diff --git a/templates/message.php b/templates/message.php
index be874e8d..94e996fc 100644
--- a/templates/message.php
+++ b/templates/message.php
@@ -1 +1,2 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <?php print $tMessage; ?>
diff --git a/templates/overview-get.php b/templates/overview-get.php
index 5ae4ab40..89c44375 100644
--- a/templates/overview-get.php
+++ b/templates/overview-get.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="overview">
 <form name="overview" method="get">
 <select class="flat" name="domain" onChange="this.form.submit();">
diff --git a/templates/password.php b/templates/password.php
index 9ca8b484..bf71a8e5 100644
--- a/templates/password.php
+++ b/templates/password.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="mailbox" method="post">
 <table>
diff --git a/templates/search.php b/templates/search.php
index 9d2da70f..4c4a8a07 100644
--- a/templates/search.php
+++ b/templates/search.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="overview">
 <form name="search" method="post" action="search.php">
 <table width=750><tr>
diff --git a/templates/sendmail.php b/templates/sendmail.php
index dd95558e..1f838140 100644
--- a/templates/sendmail.php
+++ b/templates/sendmail.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="mailbox" method="post">
 <table>
diff --git a/templates/users_edit-alias.php b/templates/users_edit-alias.php
index 85da48d2..e2aeb49a 100644
--- a/templates/users_edit-alias.php
+++ b/templates/users_edit-alias.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="alias" method="post">
 <table>
diff --git a/templates/users_login.php b/templates/users_login.php
index cebdb2cb..f04e6bdf 100644
--- a/templates/users_login.php
+++ b/templates/users_login.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="login">
 <form name="login" method="post">
 <table id="login_table" cellspacing="10">
diff --git a/templates/users_main.php b/templates/users_main.php
index 11126601..217433a8 100644
--- a/templates/users_main.php
+++ b/templates/users_main.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="main_menu">
 <table>
    <tr>
diff --git a/templates/users_menu.php b/templates/users_menu.php
index c17766c8..526b741d 100644
--- a/templates/users_menu.php
+++ b/templates/users_menu.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="menu">
 <ul>
    <li><a target="_top" href="<?php print $CONF['user_footer_link']; ?>"><?php print $PALANG['pMenu_main']; ?></a></li>
diff --git a/templates/users_password.php b/templates/users_password.php
index 100682fe..33861f9b 100644
--- a/templates/users_password.php
+++ b/templates/users_password.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="alias" method="post">
 <table>
diff --git a/templates/users_vacation.php b/templates/users_vacation.php
index a6604952..8a09a6ef 100644
--- a/templates/users_vacation.php
+++ b/templates/users_vacation.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="edit_form">
 <form name="vacation" method="post">
 <table>
diff --git a/templates/viewlog.php b/templates/viewlog.php
index c18c62e8..0260fa0a 100644
--- a/templates/viewlog.php
+++ b/templates/viewlog.php
@@ -1,3 +1,4 @@
+<?php if( !defined('POSTFIXADMIN') ) die( "This file cannot be used standalone." ); ?>
 <div id="overview">
 <form name="overview" method="post">
 <select name="fDomain" onChange="this.form.submit();">