try to disable Solve when no solution

Sudoku/SudokuFeld.svg

@@ -89,7 +89,17 @@
    		-ms-user-select: none;
    		user-select: none;
 		pointer-events: none;
-
+        fill: black;
+	}
+	.disabledActionbuttons {
+		font-size: 8px; 
+		font-family: sans-serif;
+		-webkit-user-select: none;
+  		-moz-user-select: none;
+   		-ms-user-select: none;
+   		user-select: none;
+		pointer-events: none;
+        fill: darkgray;
 	}
 	.normalNumbers {
 		font-size: 8px; 
@@ -1066,20 +1076,20 @@
 <g id="Add" transform="translate(125,22.5)">
   <title>(not available)</title>
   <ellipse ry="7" rx="7" id="AddCircle" cy="7.5" cx="7.5" class="normalKeyboard"/>
-  <text style="cursor: move;" font-style="normal" class="normalActionbuttons" font-weight="normal" xml:space="preserve" text-anchor="start" font-family="sans-serif" font-size="10" id="AddText" y="10.96203" x="4.71516" stroke-width="0" stroke="null" fill="darkgray">+</text>
+  <text style="cursor: move;" font-style="normal" class="disabledActionbuttons" font-weight="normal" xml:space="preserve" text-anchor="start" font-family="sans-serif" font-size="10" id="AddText" y="10.96203" x="4.71516" stroke-width="0" stroke="null">+</text>
  </g>
  
  <g id="Remove" transform="translate(140,22.5)">
   <title>Erase cell value</title>
   <ellipse ry="7" rx="7" id="RemoveCircle" cy="7.5" cx="7.5" class="normalKeyboard"/>
-  <text style="cursor: move;" font-style="normal" class="normalActionbuttons" font-weight="normal" xml:space="preserve" text-anchor="start" font-family="sans-serif" font-size="10" id="RemoveText" y="10" x="6" stroke-width="0" stroke="null" fill="black">-</text>
+  <text style="cursor: move;" font-style="normal" class="normalActionbuttons" font-weight="normal" xml:space="preserve" text-anchor="start" font-family="sans-serif" font-size="10" id="RemoveText" y="10" x="6" stroke-width="0" stroke="null">-</text>
  </g>
 
 
 <g id="Solve" transform="translate(155,22.5)">
   <title>Solve the puzzle automatically</title>
   <ellipse ry="7" rx="7" id="SolveCircle" cy="7.5" cx="7.5" class="normalKeyboard"/>
-  <text style="cursor: move;" transform= "scale(-1,1) rotate(-40 -9 9)" font-style="normal" class="normalActionbuttons" font-weight="normal" xml:space="preserve" text-anchor="start" font-family="sans-serif" font-size="10" id="SolveText" y="11" x="-9" stroke-width="0" stroke="null" fill="black">L</text>
+  <text style="cursor: move;" transform= "scale(-1,1) rotate(-40 -9 9)" font-style="normal" class="normalActionbuttons" font-weight="normal" xml:space="preserve" text-anchor="start" font-family="sans-serif" font-size="10" id="SolveText" y="11" x="-9" stroke-width="0" stroke="null">L</text>
  </g>
 
 <g id="SmallBoxes">

Sudoku/visb_sudoku.json

@@ -40,6 +40,11 @@
       "id": "TipFrame_%0",
       "attr": "class",
       "value" : "IF %0:PossibleVals(curx,cury) THEN \"OnTipFrames\" ELSE \"OffTipFrames\" END"
+    },
+	{
+	  "id": "SolveText",
+      "attr": "class",
+      "value" : "IF ENABLED(\"Solve\")=TRUE THEN \"normalActionbuttons\" ELSE \"disabledActionbuttons\" END"
     }
 ],
   "events": [