Simplified JQuery

ws/Docbook/Preprocess/docbooksupplement.js

 jQuery.fn.extend({
 
     toggleVisibilityState: function() {
-        var ATT_TOGGLE_VALUES = [
-        // attribute,  closed state                                      , open state
-            ['value', '+',                                                 '-'],
-            ['title', 'open solution (Did you try hard enough yourself?)', 'Close solution']
-        ];
-        var nextIndex;
-        switch(this.attr(ATT_TOGGLE_VALUES[0][0])) { // First attribute defines reference
-            case ATT_TOGGLE_VALUES[0][1]:
-                nextIndex = 2; break;
+        switch(this.attr('value')) { // »value« attribute defines state
+            case '+':
+                this.attr('value', '-');
+                this.attr('title', 'Close solution');
+                break;
             default:
-                nextIndex = 1; break;
-        }
-        for (var r in ATT_TOGGLE_VALUES) {
-            this.attr(ATT_TOGGLE_VALUES[r][0], ATT_TOGGLE_VALUES[r][nextIndex]);
+                this.attr('value', '+');
+                this.attr('title', 'open solution (Did you try hard enough yourself?)');
+                break;
         }
     }
 });