use ENABLED function

Waterboiler/visb_wasserkocher.json

@@ -19,7 +19,8 @@
     {
       "id": "turn_on",
       "attr": "opacity",
-      "value": "IF deckel_zu=TRUE & an=FALSE THEN 1.0 ELSE 0.4 END"
+      "comment": "IF deckel_zu=TRUE & an=FALSE THEN 1.0 ELSE 0.4 END",
+      "value": "IF ENABLED(\"an\")=TRUE THEN 1.0 ELSE 0.4 END"
     },
     {
       "id": "turn_off",
@@ -32,19 +33,19 @@
       "id": "turn_on",
       "event": "an",
       "hovers": [{ "attr":"stroke-width", "enter":"6", "leave":"1"},
-                 { "attr":"opacity", "enter":"0.8", "leave":"1.0"}]
+                 { "attr":"opacity", "enter":"0.75", "leave":"1.0"}]
     },
     {
       "id": "cap_closed",
       "event": "deckel_auf",
       "hovers": [{ "attr":"stroke-width", "enter":"6", "leave":"1"},
-                 { "attr":"opacity", "enter":"0.8", "leave":"1.0"}]
+                 { "attr":"opacity", "enter":"0.75", "leave":"1.0"}]
     },
     {
       "id": "cap_open",
       "event": "deckel_zu",
       "hovers": [{ "attr":"stroke-width", "enter":"6", "leave":"1"},
-                 { "attr":"opacity", "enter":"0.8", "leave":"1.0"}]
+                 { "attr":"opacity", "enter":"0.7", "leave":"1.0"}]
     }
   ]
 }

Waterboiler/waterheater.svg

-<svg height="240" width="200"
+<svg height="250" width="200"
    xmlns="http://www.w3.org/2000/svg"
    xmlns:xlink="http://www.w3.org/1999/xlink"
    >
-    <text  text-align="left"  x="50"  y="230"
-        font-family="sans-serif">
+    <text  text-align="left"  x="50"  y="235"
+        font-family="sans-serif" font-size = "11">
        <tspan dx="0" dy = "0.6em" id="visb_debug_messages">1.</tspan>
     </text>