diff --git a/400-SOURCECODE/AIAHTML5.Web/app/controllers/DAController.js b/400-SOURCECODE/AIAHTML5.Web/app/controllers/DAController.js
index 5b77de5..3f2bc7d 100644
--- a/400-SOURCECODE/AIAHTML5.Web/app/controllers/DAController.js
+++ b/400-SOURCECODE/AIAHTML5.Web/app/controllers/DAController.js
@@ -1335,6 +1335,8 @@ function ($scope, $rootScope, $compile, $http, $log, $location, $timeout, DA, Mo
 
             if (evt.ctrlKey) {
                 $rootScope.multiAnnotationIsON = true;
+
+                document.getElementById("btnZoom").setAttribute('disabled', 'disabled');
             }
             else {
                 if (($rootScope.previousHighlightList != null || $rootScope.previousHighlightList != undefined) && ($rootScope.previousHighlightList.length > 0)) {
@@ -1342,6 +1344,8 @@ function ($scope, $rootScope, $compile, $http, $log, $location, $timeout, DA, Mo
                 }
 
                 $rootScope.multiAnnotationIsON = false;
+
+                document.getElementById("btnZoom").disabled = false;
             }
 
             //get mouse coordinate of mirror image click