diff --git a/libs/plugins/function.popup.php b/libs/plugins/function.popup.php
index 96adc01e..203a3b8f 100644
--- a/libs/plugins/function.popup.php
+++ b/libs/plugins/function.popup.php
@@ -67,7 +67,7 @@ function smarty_function_popup($params, &$smarty)
     if (isset($delay)) { $retval .= ",DELAY,$delay"; }
     if (!empty($hauto)) { $retval .= ",HAUTO"; }
     if (!empty($vauto)) { $retval .= ",VAUTO"; }
-    $retval .= ');" onMouseOut="nd();"';
+    $retval .= ');" onmouseout="nd();"';
 	
 	return $retval;
 }