diff --git a/Global_Indexer/ClassControls.vb b/Global_Indexer/ClassControls.vb
index 534898e..6a363d3 100644
--- a/Global_Indexer/ClassControls.vb
+++ b/Global_Indexer/ClassControls.vb
@@ -374,7 +374,7 @@ Public Class ClassControls
             }
         }
 
-        If Vorgabe = "NULL" Then
+        If Vorgabe.ToUpper = "NULL" Then
             oPicker.EditValue = Nothing
         End If