diff --git a/htdocs/admin/multicurrency.php b/htdocs/admin/multicurrency.php
index fa622a7ee81..9602f9c383b 100644
--- a/htdocs/admin/multicurrency.php
+++ b/htdocs/admin/multicurrency.php
@@ -249,7 +249,7 @@ if (!empty($conf->global->MAIN_MULTICURRENCY_ALLOW_SYNCHRONIZATION))
 	print '<td>'.$form->textwithpicto($langs->trans("CurrencyLayerAccount"), $langs->trans("CurrencyLayerAccount_help_to_synchronize", $urlforapilayer)).'</td>'."\n";
 	print '<td class="right">';
 	print '<textarea id="response" class="hideobject" name="response"></textarea>';
-	print $langs->trans("Value").'&nbsp;<input type="button" id="bt_sync" name="bt_sync_apilayer" class="button" value="'.$langs->trans('Synchronize').'" />';
+	print $langs->trans("Value").'&nbsp;<input type="submit" id="bt_sync" name="bt_sync_apilayer" class="button" value="'.$langs->trans('Synchronize').'" />';
 	print '<input type="submit" name="modify_apilayer" class="button" value="'.$langs->trans("Modify").'">';
 	print '</td></tr>';
 
@@ -328,6 +328,15 @@ foreach ($TCurrency as &$currency)
 print '</table>';
 print '</div>';
 
+print '
+	<script type="text/javascript">
+ 		function getRates()
+		{
+			$("#bt_sync").attr("disabled", true);
+            return true;
+		}
+	</script>
+';
 
 // End of page
 llxFooter();
diff --git a/htdocs/multicurrency/class/multicurrency.class.php b/htdocs/multicurrency/class/multicurrency.class.php
index 42d53db20ad..faf05bdc571 100644
--- a/htdocs/multicurrency/class/multicurrency.class.php
+++ b/htdocs/multicurrency/class/multicurrency.class.php
@@ -626,14 +626,18 @@ class MultiCurrency extends CommonObject
 	/**
 	 * Sync rates from api
 	 *
-	 * @param 	string  $key    Key to use. Come from $conf->global->MULTICURRENCY_APP_ID.
+	 * @param 	string  $key                Key to use. Come from $conf->global->MULTICURRENCY_APP_ID.
+	 * @param   int     $addifnotfound      Add if not found
      * @return  void
 	 */
-	public static function syncRates($key)
+	public static function syncRates($key, $addifnotfound = 0)
 	{
 		global $conf, $db, $langs;
 
 		$urlendpoint = 'http://apilayer.net/api/live?access_key='.$key;
+		//$urlendpoint.='&format=1';
+		$urlendpoint.=(empty($conf->global->MULTICURRENCY_APP_SOURCE) ? '' : '&source='.$conf->global->MULTICURRENCY_APP_SOURCE);
+
 		dol_syslog("Call url endpoint ".$urlendpoint);
 
 		// TODO Use getURLContent() function instead.
@@ -658,7 +662,7 @@ class MultiCurrency extends CommonObject
 					{
 						$obj->updateRate($rate);
 					}
-					else
+					elseif ($addifnotfound)
 					{
 						self::addRateFromDolibarr($code, $rate);
 					}