diff --git a/web/gui/src/main/webapp/app/fw/widget/button.js b/web/gui/src/main/webapp/app/fw/widget/button.js
index 2ef5b4b..734cb10 100644
--- a/web/gui/src/main/webapp/app/fw/widget/button.js
+++ b/web/gui/src/main/webapp/app/fw/widget/button.js
@@ -240,7 +240,8 @@
         return {
             width: rsetWidth,
             selected: selected,
-            selectedIndex: selectedIndex
+            selectedIndex: selectedIndex,
+            size: function () { return rads.length; }
         }
     }
 
diff --git a/web/gui/src/main/webapp/app/view/topo/topo.js b/web/gui/src/main/webapp/app/view/topo/topo.js
index 3564eb3..ace9a0e 100644
--- a/web/gui/src/main/webapp/app/view/topo/topo.js
+++ b/web/gui/src/main/webapp/app/view/topo/topo.js
@@ -65,6 +65,13 @@
 
             E: [equalizeMasters, 'Equalize mastership roles'],
 
+            // topology overlay selections
+            F1: function () { ttbs.fnkey(0); },
+            F2: function () { ttbs.fnkey(1); },
+            F3: function () { ttbs.fnkey(2); },
+            F4: function () { ttbs.fnkey(3); },
+            F5: function () { ttbs.fnkey(4); },
+
             esc: handleEscape,
 
             _keyListener: ttbs.keyListener,
diff --git a/web/gui/src/main/webapp/app/view/topo/topoPanel.js b/web/gui/src/main/webapp/app/view/topo/topoPanel.js
index 748c17f..af2c4bc 100644
--- a/web/gui/src/main/webapp/app/view/topo/topoPanel.js
+++ b/web/gui/src/main/webapp/app/view/topo/topoPanel.js
@@ -97,7 +97,9 @@
                 $log.warn('adjustHeight: height from top of page not given');
                 return null;
             } else if (!body || !p) {
-                $log.warn('adjustHeight: panel contents are not defined');
+                // panel contents are not defined
+                // this may happen when window is resizing but panel has
+                //   been cleared or removed
                 return null;
             }
 
diff --git a/web/gui/src/main/webapp/app/view/topo/topoToolbar.js b/web/gui/src/main/webapp/app/view/topo/topoToolbar.js
index fbcdaf6..c62e52b 100644
--- a/web/gui/src/main/webapp/app/view/topo/topoToolbar.js
+++ b/web/gui/src/main/webapp/app/view/topo/topoToolbar.js
@@ -270,6 +270,13 @@
         ovRset.selectedIndex(idx);
     }
 
+    // an overlay was selected via Function-Key press
+    function fnkey(idx) {
+        if (idx < ovRset.size() && idx !== ovRset.selectedIndex()) {
+            ovRset.selectedIndex(idx);
+        }
+    }
+
     angular.module('ovTopo')
         .factory('TopoToolbarService',
         ['$log', 'FnService', 'ToolbarService', 'PrefsService',
@@ -289,7 +296,8 @@
                 destroyToolbar: destroyToolbar,
                 keyListener: keyListener,
                 toggleToolbar: toggleToolbar,
-                setDefaultOverlay: setDefaultOverlay
+                setDefaultOverlay: setDefaultOverlay,
+                fnkey: fnkey
             };
         }]);
 }());
\ No newline at end of file