diff --git a/admin/environment.php b/admin/environment.php
index 08927756a6d..89871e57d78 100644
--- a/admin/environment.php
+++ b/admin/environment.php
@@ -1,4 +1,4 @@
-<?php  //$Ia:d$
+<?php  //$Id$
 
 ///////////////////////////////////////////////////////////////////////////
 //                                                                       //
@@ -46,6 +46,57 @@ define(NO_PHP_EXTENSIONS_SECTION_FOUND,   10);
 define(NO_PHP_EXTENSIONS_NAME_FOUND,      11);
 define(NO_PHP_EXTENSION_WITH_NAME,        12);
 
+
+
+
+//--- Presentation functions to display all the interface ---//
+
+
+
+
+
+
+
+
+
+
+//--- Logic functions to parse and detect everything ---//
+
+/**
+ * This function will perform the whole check, returning
+ * true or false as final result. Also, he full array of
+ * environment_result will be returned in the parameter list.
+ * The function looks for the best version to compare and
+ * everything. This is the only function that should be called
+ * ever from the rest of Moodle.
+ * @param string version version to check. 
+ * @param array results array of results checked.
+ * @return boolean true/false, depending of results
+ */
+function check_moodle_environment($version, &$environment_results) {
+
+/// Get the more recent version before the requested
+    if (!$version = get_latest_version_available($version)) {
+        return false;
+    }
+
+/// Perform all the checks
+    if(!$environment_results = environment_check($version)) {
+        return false;
+    }
+
+/// Iterate over all the results looking for some error in required items
+    foreach ($environment_results as $environment_result) {
+        if (empty($environment_result->result) && $environment_result->level == 'required') {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+
+
 /**
  * This function will normalize any version to just a serie of numbers
  * separated by dots. Everything else will be removed.
@@ -113,12 +164,52 @@ function get_list_of_environment_versions ($contents) {
     return $versions;
 }
 
+/**
+ * This function will return the most recent version in the environment.xml
+ * file previous or equal to the version requested
+ * @param string version top version from which we start to look backwards
+ * @return string more recent version or false if not found
+ */
+function get_latest_version_available ($version) {
+
+/// Normalize the version requested
+    $version = normalize_version($version);
+
+/// Load xml file
+    if (!$contents = load_environment_xml()) {
+        return false;
+    }
+
+/// Detect available versions
+    if (!$versions = get_list_of_environment_versions($contents)) {
+        return false;
+    }
+/// First we look for exact version
+    if (in_array($version, $versions)) {
+        return $version;
+    } else {
+        $found_version = false;
+    /// Not exact match, so we are going to iterate over the list searching
+    /// for the latest version before the requested one
+        foreach ($versions as $arrversion) {
+            if (version_compare($arrversion, $version, '<')) {
+                $found_version = $arrversion;
+            }
+        }
+    }
+
+    return $found_version;
+}
+
 /** 
  * This function will return the xmlized data belonging to one Moodle version
  * @return mixed the xmlized structure or false on error
  */
 function get_environment_for_version($version) {
    
+/// Normalize the version requested
+    $version = normalize_version($version);
+
 /// Load xml file
     if (!$contents = load_environment_xml()) {
         return false;
@@ -148,6 +239,9 @@ function get_environment_for_version($version) {
  */
 function environment_check($version) {
 
+/// Normalize the version requested
+    $version = normalize_version($version);
+
     $results = array(); //To store all the results
 
     $results[] = environment_check_database($version);
@@ -172,6 +266,7 @@ function environment_check_php_extensions($version) {
 /// Get the enviroment version we need
     if (!$data = get_environment_for_version($version)) {
     /// Error. No version data found
+        $result = new environment_results('php_extensions');
         $result->setStatus(false);
         $result->setErrorCode(NO_VERSION_DATA_FOUND);
         return $result;
@@ -180,6 +275,7 @@ function environment_check_php_extensions($version) {
 /// Extract the php_extension part
     if (!isset($data['#']['PHP_EXTENSIONS']['0']['#']['PHP_EXTENSION'])) {
     /// Error. No PHP section found
+        $result = new environment_results('php_extensions');
         $result->setStatus(false);
         $result->setErrorCode(NO_PHP_EXTENSIONS_SECTION_FOUND);
         return $result;
@@ -190,7 +286,7 @@ function environment_check_php_extensions($version) {
         /// Check for level
             if (isset($extension['@']['level'])) {
                 $level = $extension['@']['level'];
-                if ($level != 'recommended') {
+                if ($level != 'optional') {
                     $level = 'required';
                 }
             }
@@ -245,7 +341,7 @@ function environment_check_php($version) {
     /// Extract level and version
         if (isset($data['#']['PHP']['0']['@']['level'])) {
             $level = $data['#']['PHP']['0']['level'];
-            if ($level != 'recommended') {
+            if ($level != 'optional') {
                 $level = 'required';
             }
         }
@@ -306,7 +402,7 @@ function environment_check_database($version) {
     /// Extract level
         if (isset($data['#']['DATABASE']['0']['@']['level'])) {
             $level = $data['#']['DATABASE']['0']['level'];
-            if ($level != 'recommended') {
+            if ($level != 'optional') {
                 $level = 'required';
             }
         }
@@ -366,6 +462,10 @@ function environment_check_database($version) {
 
 //--- Helper Class to return results to caller ---//
 
+
+
+
+
 /** 
  * This class is used to return the results of the environment
  * main functions (environment_check_xxxx)
@@ -374,7 +474,7 @@ class environment_results {
 
     var $result;          //true/false
     var $error_code;      //integer. See constants at the beginning of the file
-    var $level;           //required/recommended
+    var $level;           //required/optional
     var $current_version; //current version detected
     var $needed_version;  //version needed
     var $info;            //Aux. info (DB vendor, library...)
@@ -413,7 +513,7 @@ class environment_results {
 
     /**
      * Set the level
-     * @param string the level (required, recommended)
+     * @param string the level (required, optional)
      */
      function setLevel($level) {
          $this->level=$level;
@@ -444,6 +544,4 @@ class environment_results {
      }
 }
 
-
-
 ?>