Implement automatic web search tab switching on empty local result

When a local search occurs (not triggered by explict tab click),
automatically switch to the "All of UNL" tab if no result are detected.

www/js/search.js

@@ -146,6 +146,7 @@
 				directorySearch,
 				localContext = window['LOCAL_SEARCH_CONTEXT'],
 				drawOp = new google.search.DrawOptions(),
+				searchToggleLock = false,
 				
 				trackQuery = function(q) {
 					var loc = window.location,
@@ -175,8 +176,15 @@
 					});
 					$('img.gcsc-branding-img-noclear', $root).attr('alt', 'Google™');
 					
+					if (!searchToggleLock && control == localSearch && $('.gs-no-results-result').length) {
+						$root.closest('.results-group').find('.result-tab li:last-child').click();
+						return;
+					}
+					
 					$root.closest(resultSel).addClass(actCls);
 					$root.closest(googleSel).slideDown();
+					
+					searchToggleLock = false;
 				},
 				fullQuery = function(q, track) {
 					if (track !== false) {
@@ -288,6 +296,7 @@
 					if ($par.is(wrapperDir)) {
 						directorySearch.changeViewState(i);
 					} else if ($par.is(wrapperWeb)) {
+						searchToggleLock = true;
 						$(activeSearch.root).closest(googleSel).slideUp().trigger(evtStateChange, [i, 0 + !i]);
 						if (i === 0) {
 							activeSearch = localSearch;