diff --git a/content/treestyletab/res/extensions.js b/content/treestyletab/res/extensions.js
index d38c7f20..535d827f 100644
--- a/content/treestyletab/res/extensions.js
+++ b/content/treestyletab/res/extensions.js
@@ -9,13 +9,13 @@
    //     window['piro.sakura.ne.jp'].extensions.isEnabled('my.extension.id@example.com'))
    //     window['piro.sakura.ne.jp'].extensions.goToOptions('my.extension.id@example.com');
 
- lisence: The MIT License, Copyright (c) 2009 SHIMODA "Piro" Hiroshi
+ lisence: The MIT License, Copyright (c) 2009-2010 SHIMODA "Piro" Hiroshi
    http://www.cozmixng.org/repos/piro/fx3-compatibility-lib/trunk/license.txt
  original:
    http://www.cozmixng.org/repos/piro/fx3-compatibility-lib/trunk/extensions.js
 */
 (function() {
-	const currentRevision = 2;
+	const currentRevision = 3;
 
 	if (!('piro.sakura.ne.jp' in window)) window['piro.sakura.ne.jp'] = {};
 
@@ -26,11 +26,35 @@
 		return;
 	}
 
+	// Firefox 3.7 or later
+	var AM = {};
+	if ('@mozilla.org/addons/integration;1' in Components.classes)
+		Components.utils.import('resource://gre/modules/AddonManager.jsm', AM);
+
 	window['piro.sakura.ne.jp'].extensions = {
 		revision : currentRevision,
 
-		ExtensionManager : Components.classes['@mozilla.org/extensions/manager;1']
-			.getService(Components.interfaces.nsIExtensionManager),
+		// Firefox 3.7 or later
+		getInstalledAddon : function(aId)
+		{
+			var addon;
+			AM.AddonManager.getAddonByID(aId, function(aAddon) {
+				addon = aAddon;
+			});
+			var thread = Components.classes['@mozilla.org/thread-manager;1']
+							.getService()
+							.mainThread;
+			while (addon === void(0)) {
+				thread.processNextEvent(true);
+			}
+			return addon;
+		},
+
+		// Firefox 3.6 or older
+		ExtensionManager : ('@mozilla.org/extensions/manager;1' in Components.classes) ?
+			Components.classes['@mozilla.org/extensions/manager;1']
+				.getService(Components.interfaces.nsIExtensionManager) :
+			null,
 		RDF : Components.classes['@mozilla.org/rdf/rdf-service;1']
 			.getService(Components.interfaces.nsIRDFService),
 		WindowMediator : Components.classes['@mozilla.org/appshell/window-mediator;1']
@@ -39,16 +63,38 @@
 			.getService(Components.interfaces.nsIPrefBranch),
 
 		isAvailable : function(aId)
+		{
+			return this.ExtensionManager ? this.isAvailable_EM(aId) : this.isAvailable_AM(aId) ;
+		},
+		isAvailable_EM : function(aId)
 		{
 			return this.isInstalled(aId) && this.isEnabled(aId);
 		},
+		isAvailable_AM : function(aId)
+		{
+			var addon = this.getInstalledAddon(aId);
+			if (!addon) return false;
+			return addon.isActive;
+		},
 
 		isInstalled : function(aId)
+		{
+			return this.ExtensionManager ? this.isInstalled_EM(aId) : this.isInstalled_AM(aId) ;
+		},
+		isInstalled_EM : function(aId)
 		{
 			return this.ExtensionManager.getInstallLocation(aId);
 		},
+		isInstalled_AM : function(aId)
+		{
+			return this.getInstalledAddon(aId);
+		},
 
 		isEnabled : function(aId)
+		{
+			return this.ExtensionManager ? this.isEnabled_EM(aId) : this.isEnabled_AM(aId) ;
+		},
+		isEnabled_EM : function(aId)
 		{
 			var res  = this.RDF.GetResource('urn:mozilla:item:'+aId);
 			var appDisabled = false;
@@ -76,21 +122,14 @@
 
 			return !appDisabled && !userDisabled;
 		},
+		isEnabled_AM : function(aId)
+		{
+			return false;
+		},
 
 		goToOptions : function(aId)
 		{
-			var res  = this.RDF.GetResource('urn:mozilla:item:'+aId);
-			var uri;
-			try {
-				uri = this.ExtensionManager.datasource.GetTarget(
-						res,
-						this.RDF.GetResource('http://www.mozilla.org/2004/em-rdf#optionsURL'),
-						true
-					).QueryInterface(Components.interfaces.nsIRDFLiteral)
-					.Value;
-			}
-			catch(e) {
-			}
+			var uri = this.ExtensionManager ? this.getOptionsURI_EM(aId) : this.getOptionsURI_AM(aId) ;
 			if (!uri) return;
 
 			var windows = this.WindowMediator.getEnumerator(null);
@@ -113,6 +152,28 @@
 				'',
 				'chrome,titlebar,toolbar,centerscreen,' + (instantApply ? 'dialog=no' : 'modal' )
 			);
+		},
+		getOptionsURI_EM : function(aId)
+		{
+			var res  = this.RDF.GetResource('urn:mozilla:item:'+aId);
+			var uri;
+			try {
+				uri = this.ExtensionManager.datasource.GetTarget(
+						res,
+						this.RDF.GetResource('http://www.mozilla.org/2004/em-rdf#optionsURL'),
+						true
+					).QueryInterface(Components.interfaces.nsIRDFLiteral)
+					.Value;
+			}
+			catch(e) {
+			}
+			return uri;
+		},
+		getOptionsURI_AM : function(aId)
+		{
+			var addon = this.getInstalledAddon(aId);
+			if (!addon || !addon.isActive) return null;
+			return addon.optionsURL;
 		}
 	};
 })();