diff --git a/javascript/SitetreeAccess.js b/javascript/SitetreeAccess.js
new file mode 100644
index 00000000..664fa37a
--- /dev/null
+++ b/javascript/SitetreeAccess.js
@@ -0,0 +1,60 @@
+/**
+ * UI behaviour for the "Access" tab
+ *
+ * Adapted from the forum module "ForumAccess.js" file.
+ *
+ * @author Markus Lanthaler <markus@silverstripe.com>
+ */
+
+ViewersGroupHide = function() {
+	$('ViewersGroup').style.display = "none";
+}
+EditorsGroupHide = function() {
+	$('EditorsGroup').style.display = "none";
+}
+
+Behaviour.register({
+	'#Form_EditForm_Viewers_OnlyTheseUsers': {
+
+		onclick: function() {
+			$('ViewersGroup').style.display = "block";
+		},
+
+		initialize: function() {
+			if($('Form_EditForm_Viewers_OnlyTheseUsers')) {
+				if($('Form_EditForm_Viewers_OnlyTheseUsers').checked)
+					$('ViewersGroup').style.display = "block";
+				else
+					$('ViewersGroup').style.display = "none";
+			}
+		}
+	},
+
+	'#Form_EditForm_Viewers_Anyone': {
+		onclick: ViewersGroupHide
+	},
+
+	'#Form_EditForm_Viewers_LoggedInUsers': {
+		onclick: ViewersGroupHide
+	},
+
+	'#Form_EditForm_Editors_OnlyTheseUsers': {
+
+		onclick: function() {
+			$('EditorsGroup').style.display = "block";
+		},
+
+		initialize: function() {
+			if($('Form_EditForm_Editors_OnlyTheseUsers')) {
+				if($('Form_EditForm_Editors_OnlyTheseUsers').checked)
+					$('EditorsGroup').style.display = "block";
+				else
+					$('EditorsGroup').style.display = "none";
+			}
+		}
+	},
+
+	'#Form_EditForm_Editors_LoggedInUsers': {
+		onclick: EditorsGroupHide
+	}
+});
\ No newline at end of file