diff --git a/htdocs/product/class/priceexpression.class.php b/htdocs/product/dynamic_price/class/price_expression.class.php
similarity index 92%
rename from htdocs/product/class/priceexpression.class.php
rename to htdocs/product/dynamic_price/class/price_expression.class.php
index c5e24d3a228..babf86235c0 100644
--- a/htdocs/product/class/priceexpression.class.php
+++ b/htdocs/product/dynamic_price/class/price_expression.class.php
@@ -1,7 +1,7 @@
 <?php
 /* Copyright (C) 2007-2012 Laurent Destailleur  <eldy@users.sourceforge.net>
  * Copyright (C) 2014	   Juanjo Menent		<jmenent@2byte.es>
-/* Copyright (C) 2014      Ion Agorria          <ion@agorria.com>
+/* Copyright (C) 2015      Ion Agorria          <ion@agorria.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,7 +18,7 @@
  */
 
 /**
- *	\file       htdocs/product/class/priceexpression.class.php
+ *	\file       htdocs/product/expression/class/price_expression.class.php
  *	\ingroup    product
  *  \brief      Class for accessing price expression table
  */
@@ -35,6 +35,7 @@ class PriceExpression
     var $id;
     var $title;
 	var $expression;
+    public $table_element = "c_price_expression";
 
     /**
      *  Constructor
@@ -57,14 +58,14 @@ class PriceExpression
      */
     function create($user, $notrigger=0)
     {
-		$error=0;
+        $error=0;
 
 		// Clean parameters
 		if (isset($this->title)) $this->title=trim($this->title);
 		if (isset($this->expression)) $this->expression=trim($this->expression);
 
         // Insert request
-		$sql = "INSERT INTO ".MAIN_DB_PREFIX."c_price_expression (";
+		$sql = "INSERT INTO ".MAIN_DB_PREFIX.$this->table_element." (";
 		$sql.= "title, expression";
 		$sql.= ") VALUES (";
 		$sql.= " ".(isset($this->title)?"'".$this->db->escape($this->title)."'":"''").",";
@@ -121,7 +122,7 @@ class PriceExpression
     function fetch($id)
     {
         $sql = "SELECT title, expression";
-        $sql.= " FROM ".MAIN_DB_PREFIX."c_price_expression";
+        $sql.= " FROM ".MAIN_DB_PREFIX.$this->table_element;
         $sql.= " WHERE rowid = ".$id;
 
     	dol_syslog(get_class($this)."::fetch");
@@ -133,8 +134,8 @@ class PriceExpression
             {
                 $this->id			= $id;
                 $this->title		= $obj->title;
-				$this->expression	= $obj->expression;
-            	return 1;
+                $this->expression	= $obj->expression;
+                return 1;
             }
             else
             {
@@ -156,10 +157,10 @@ class PriceExpression
     function list_price_expression()
     {
         $sql = "SELECT rowid, title, expression";
-        $sql.= " FROM ".MAIN_DB_PREFIX."c_price_expression";
+        $sql.= " FROM ".MAIN_DB_PREFIX.$this->table_element;
         $sql.= " ORDER BY title";
 
-    	dol_syslog(get_class($this)."::list_price_expression");
+        dol_syslog(get_class($this)."::list_price_expression");
         $resql=$this->db->query($sql);
         if ($resql)
         {
@@ -194,7 +195,7 @@ class PriceExpression
     function find_title($title)
     {
         $sql = "SELECT rowid";
-        $sql.= " FROM ".MAIN_DB_PREFIX."c_price_expression";
+        $sql.= " FROM ".MAIN_DB_PREFIX.$this->table_element;
         $sql.= " WHERE title = '".$this->db->escape($title)."'";
 
     	dol_syslog(get_class($this)."::find_title");
@@ -235,7 +236,7 @@ class PriceExpression
 		if (isset($this->expression)) $this->expression=trim($this->expression);
 
         // Update request
-        $sql = "UPDATE ".MAIN_DB_PREFIX."c_price_expression SET";
+        $sql = "UPDATE ".MAIN_DB_PREFIX.$this->table_element." SET";
 		$sql.= " title = ".(isset($this->title)?"'".$this->db->escape($this->title)."'":"''").",";
 		$sql.= " expression = ".(isset($this->expression)?"'".$this->db->escape($this->expression)."'":"''")."";
         $sql.= " WHERE rowid = ".$this->id;
@@ -309,7 +310,7 @@ class PriceExpression
 
 		if (! $error)
 		{
-    		$sql = "DELETE FROM ".MAIN_DB_PREFIX."c_price_expression";
+    		$sql = "DELETE FROM ".MAIN_DB_PREFIX.$this->table_element;
     		$sql.= " WHERE rowid = ".$rowid;
 
 	        dol_syslog(get_class($this)."::delete");
diff --git a/htdocs/product/class/priceparser.class.php b/htdocs/product/dynamic_price/class/price_parser.class.php
similarity index 78%
rename from htdocs/product/class/priceparser.class.php
rename to htdocs/product/dynamic_price/class/price_parser.class.php
index c2b047a7ae1..68367d8ba5f 100644
--- a/htdocs/product/class/priceparser.class.php
+++ b/htdocs/product/dynamic_price/class/price_parser.class.php
@@ -1,5 +1,5 @@
 <?php
-/* Copyright (C) 2014      Ion Agorria          <ion@agorria.com>
+/* Copyright (C) 2015      Ion Agorria          <ion@agorria.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,13 +16,15 @@
  */
 
 /**
- *	\file       htdocs/product/class/priceparser.class.php
+ *	\file       htdocs/product/expression/class/price_parser.class.php
  *	\ingroup    product
  *	\brief      File of class to calculate prices using expression
  */
 require_once DOL_DOCUMENT_ROOT.'/includes/evalmath/evalmath.class.php';
 require_once DOL_DOCUMENT_ROOT.'/fourn/class/fournisseur.product.class.php';
-require_once DOL_DOCUMENT_ROOT.'/product/class/priceexpression.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/dynamic_price/class/price_expression.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/dynamic_price/class/price_global_variable.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/dynamic_price/class/price_global_variable_updater.class.php';
 require_once DOL_DOCUMENT_ROOT.'/core/class/extrafields.class.php';
 
 /**
@@ -30,17 +32,17 @@ require_once DOL_DOCUMENT_ROOT.'/core/class/extrafields.class.php';
  */
 class PriceParser
 {
-    protected $db;
-    // Limit of expressions per price
-    public $limit = 100;
-    // The error that ocurred when parsing price
-    public $error;
-    // The expression that caused the error
-    public $error_expr;
-    //The special char
-    public $special_chr = "#";
-    //The separator char
-    public $separator_chr = ";";
+	protected $db;
+	// Limit of expressions per price
+	public $limit = 100;
+	// The error that occurred when parsing price
+	public $error;
+	// The expression that caused the error
+	public $error_expr;
+	//The special char
+	public $special_chr = "#";
+	//The separator char
+	public $separator_chr = ";";
 
 	/**
 	 *  Constructor
@@ -104,7 +106,7 @@ class PriceParser
 		{
 			return $langs->trans("ErrorPriceExpression".$code, $info);
 		}
-		else if (in_array($code, array(6))) //Errors which have 2 args
+		else if (in_array($code, array(6, 23))) //Errors which have 2 args
 		{
 			return $langs->trans("ErrorPriceExpression".$code, $info[0], $info[1]);
 		}
@@ -128,6 +130,7 @@ class PriceParser
 	 */
 	public function parseExpression($product, $expression, $values)
 	{
+		global $user;
 		//Accessible product values by expressions
 		$values = array_merge($values, array(
 			"tva_tx" => $product->tva_tx,
@@ -139,13 +142,31 @@ class PriceParser
 			"price_min" => $product->price_min,
 		));
 
-		//Retreive all extrafield for product and add it to values
+		//Retrieve all extrafield for product and add it to values
 		$extrafields = new ExtraFields($this->db);
 		$extralabels = $extrafields->fetch_name_optionals_label('product', true);
 		$product->fetch_optionals($product->id, $extralabels);
 		foreach ($extrafields->attribute_label as $key=>$label)
 		{
-			$values['options_'.$key] = $product->array_options['options_'.$key];
+			$values["extrafield_".$key] = $product->array_options['options_'.$key];
+		}
+
+		//Process any pending updaters
+		$price_updaters = new PriceGlobalVariableUpdater($this->db);
+		foreach ($price_updaters->listPendingUpdaters() as $entry) {
+            //Schedule the next update by adding current timestamp (secs) + interval (mins)
+            $entry->update_next_update(dol_now() + ($entry->update_interval * 60), $user);
+            //Do processing
+			$res = $entry->process();
+            //Store any error or clear status if OK
+            $entry->update_status($res < 1?$entry->error:'', $user);
+		}
+
+		//Get all global values
+		$price_globals = new PriceGlobalVariable($this->db);
+		foreach ($price_globals->listGlobalVariables() as $entry)
+		{
+			$values["global_".$entry->code] = $entry->value;
 		}
 
 		//Check if empty
@@ -153,36 +174,32 @@ class PriceParser
 		if (empty($expression))
 		{
 			$this->error = array(20, null);
-			return -1;
+			return -2;
 		}
 
 		//Prepare the lib, parameters and values
 		$em = new EvalMath();
 		$em->suppress_errors = true; //Don't print errors on page
 		$this->error_expr = null;
-		$search = array();
-		$replace = array();
-		foreach ($values as $key => $value) {
-			if ($value !== null) {
-				$search[] = $this->special_chr.$key.$this->special_chr;
-				$replace[] = $value;
-			}
-		}
+		$last_result = null;
 
 		//Iterate over each expression splitted by $separator_chr
 		$expression = str_replace("\n", $this->separator_chr, $expression);
+		foreach ($values as $key => $value)
+		{
+			$expression = str_replace($this->special_chr.$key.$this->special_chr, "$value", $expression);
+		}
 		$expressions = explode($this->separator_chr, $expression);
-		$expressions = array_slice($expressions, 0, $limit);
+		$expressions = array_slice($expressions, 0, $this->limit);
 		foreach ($expressions as $expr) {
 			$expr = trim($expr);
 			if (!empty($expr))
 			{
-				$expr = str_ireplace($search, $replace, $expr);
 				$last_result = $em->evaluate($expr);
 				$this->error = $em->last_error_code;
 				if ($this->error !== null) { //$em->last_error is null if no error happened, so just check if error is not null
 					$this->error_expr = $expr;
-					return -2;
+					return -3;
 				}
 			}
 		}
@@ -190,15 +207,15 @@ class PriceParser
 		if (empty($vars["price"])) {
 			$vars["price"] = $last_result;
 		}
-		if ($vars["price"] === null)
+		if (!isset($vars["price"]))
 		{
 			$this->error = array(21, $expression);
-			return -3;
+			return -4;
 		}
 		if ($vars["price"] < 0)
 		{
 			$this->error = array(22, $expression);
-			return -4;
+			return -5;
 		}
 		return $vars["price"];
 	}
@@ -209,13 +226,13 @@ class PriceParser
 	 *	@param	Product				$product    	The Product object to get information
 	 *	@param	string 				$expression     The expression to parse
 	 *	@param	array 				$extra_values   Any aditional values for expression
-     *  @return int 				> 0 if OK, < 1 if KO
+	 *  @return int 				> 0 if OK, < 1 if KO
 	 */
 	public function parseProductExpression($product, $expression, $extra_values = array())
 	{
 		//Get the supplier min
-        $productFournisseur = new ProductFournisseur($this->db);
-        $supplier_min_price = $productFournisseur->find_min_price_product_fournisseur($product->id);
+		$productFournisseur = new ProductFournisseur($this->db);
+		$supplier_min_price = $productFournisseur->find_min_price_product_fournisseur($product->id);
 
 		//Accessible values by expressions
 		$extra_values = array_merge($extra_values, array(
@@ -237,7 +254,7 @@ class PriceParser
 	 *
 	 *	@param	Product				$product    	The Product object to get information
 	 *	@param	array 				$extra_values   Any aditional values for expression
-     *  @return int 								> 0 if OK, < 1 if KO
+	 *  @return int 								> 0 if OK, < 1 if KO
 	 */
 	public function parseProduct($product, $extra_values = array())
 	{
@@ -261,7 +278,7 @@ class PriceParser
 	 *	@param	int					$quantity     	Supplier Min quantity
 	 *	@param	int					$tva_tx     	Supplier VAT rate
 	 *	@param	array 				$extra_values   Any aditional values for expression
-     *  @return int 				> 0 if OK, < 1 if KO
+	 *  @return int 				> 0 if OK, < 1 if KO
 	 */
 	public function parseProductSupplierExpression($product_id, $expression, $quantity = null, $tva_tx = null, $extra_values = array())
 	{
@@ -285,7 +302,7 @@ class PriceParser
 	 *	@param	int					$quantity     	Min quantity
 	 *	@param	int					$tva_tx     	VAT rate
 	 *	@param	array 				$extra_values   Any aditional values for expression
-     *  @return int 				> 0 if OK, < 1 if KO
+	 *  @return int 				> 0 if OK, < 1 if KO
 	 */
 	public function parseProductSupplier($product_id, $expression_id, $quantity = null, $tva_tx = null, $extra_values = array())
 	{
diff --git a/htdocs/product/expression.php b/htdocs/product/dynamic_price/editor.php
similarity index 85%
rename from htdocs/product/expression.php
rename to htdocs/product/dynamic_price/editor.php
index be3e5401789..1fc7df3b731 100644
--- a/htdocs/product/expression.php
+++ b/htdocs/product/dynamic_price/editor.php
@@ -16,16 +16,17 @@
  */
 
 /**
- *  \file	   htdocs/product/expression.php
+ *  \file	   htdocs/product/expression/editor.php
  *  \ingroup	product
  *  \brief	  Page for editing expression
  */
 
-require '../main.inc.php';
+require '../../main.inc.php';
 require_once DOL_DOCUMENT_ROOT.'/core/lib/product.lib.php';
 require_once DOL_DOCUMENT_ROOT.'/fourn/class/fournisseur.product.class.php';
-require_once DOL_DOCUMENT_ROOT.'/product/class/priceexpression.class.php';
-require_once DOL_DOCUMENT_ROOT.'/product/class/priceparser.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/dynamic_price/class/price_expression.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/dynamic_price/class/price_global_variable.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/dynamic_price/class/price_parser.class.php';
 
 $langs->load("products");
 $langs->load("accountancy"); //"Back" translation is on this file
@@ -47,6 +48,7 @@ $product = new Product($db);
 $product->fetch($id, '');
 
 $price_expression = new PriceExpression($db);
+$price_globals = new PriceGlobalVariable($db);
 
 //Fetch expression data
 if (empty($eid)) //This also disables fetch when eid == 0
@@ -184,8 +186,17 @@ print '<tr><td class="fieldrequired">'.$langs->trans("Name").'</td><td>';
 print '<input class="flat" name="expression_title" size="15" value="'.($price_expression->title?$price_expression->title:'').'">';
 print '</td></tr>';
 
+//Help text
+$help_text = $langs->trans("PriceExpressionEditorHelp1");
+$help_text.= '<br><br>'.$langs->trans("PriceExpressionEditorHelp2");
+$help_text.= '<br><br>'.$langs->trans("PriceExpressionEditorHelp3");
+$help_text.= '<br><br>'.$langs->trans("PriceExpressionEditorHelp4");
+$help_text.= '<br><br>'.$langs->trans("PriceExpressionEditorHelp5");
+foreach ($price_globals->listGlobalVariables() as $entry) {
+    $help_text.= '<br><b>#globals_'.$entry->code.'#</b> '.$entry->description.' = '.$entry->value;
+}
+
 //Price expression editor
-$help_text = $langs->trans("PriceExpressionEditorHelp1").'<br><br>'.$langs->trans("PriceExpressionEditorHelp2").'<br><br>'.$langs->trans("PriceExpressionEditorHelp3").'<br><br>'.$langs->trans("PriceExpressionEditorHelp4");
 print '<tr><td class="fieldrequired">'.$form->textwithpicto($langs->trans("PriceExpressionEditor"),$help_text,1).'</td><td>';
 require_once DOL_DOCUMENT_ROOT.'/core/class/doleditor.class.php';
 $doleditor=new DolEditor('expression',isset($price_expression->expression)?$price_expression->expression:'','',300,'','',false,false,false,4,80);
@@ -194,7 +205,7 @@ print '</td></tr>';
 print '</table>';
 
 //Buttons
-print '<center>';
+print '<div style="text-align: center;">';
 print '<input type="submit" class="butAction" value="'.$langs->trans("Save").'">';
 print '<span id="back" class="butAction">'.$langs->trans("Back").'</span>';
 if ($eid == 0)
@@ -205,9 +216,9 @@ else
 {
 	print '<div class="inline-block divButAction"><a class="butActionDelete" href="'.$_SERVER["PHP_SELF"].'?id='.$id.'&amp;tab='.$tab.'&amp;eid='.$eid.'&amp;action=delete">'.$langs->trans("Delete").'</a></div>';
 }
-print '</center>';
+print '</div>';
 
-print '</form>';	
+print '</form>';
 
 // This code reloads the page depending of selected option, goes to page selected by tab when back is pressed
 print '<script type="text/javascript">
@@ -217,7 +228,7 @@ print '<script type="text/javascript">
 		jQuery("#expression_selection").change(on_change);
 	}
 	function on_click() {
-		window.location = "'.str_replace('expression.php', $tab.'.php', $_SERVER["PHP_SELF"]).'?id='.$id.($tab == 'price' ? '&action=edit_price' : '').'";
+		window.location = "'.str_replace('dynamic_price/editor.php', $tab.'.php', $_SERVER["PHP_SELF"]).'?id='.$id.($tab == 'price' ? '&action=edit_price' : '').'";
 	}
 	function on_change() {
 		window.location = "'.$_SERVER["PHP_SELF"].'?id='.$id.'&tab='.$tab.'&eid=" + $("#expression_selection").attr("value");