--- a/svghmi/svghmi.js	Wed Nov 25 14:46:25 2020 +0100
+++ b/svghmi/svghmi.js	Wed Nov 25 14:47:23 2020 +0100
@@ -264,7 +264,7 @@
     return new_val;
 }
 
-quotes = {"'":null, '"':null};
+const quotes = {"'":null, '"':null};
 
 function change_hmi_value(index, opstr) {
     let op = opstr[0];