diff --git a/contract.php b/contract.php
index d97e2ce..6e27d19 100644
--- a/contract.php
+++ b/contract.php
@@ -185,7 +185,7 @@ foreach($servicetools as $service_tool){
 }
 //get ignore list
 $ignored_serialnumbers = '';
-if (!empty($ignore_lists) || $ignore_lists != ''){ 
+if (!empty($ignore_lists)){ 
     foreach($ignore_lists as $list){
         $ignored_serialnumbers .= $list.',';
     }