Add Bookmark to Firefox Browser

function Dummy_Execute_Bookmark()
{
try
{
var mainWindow = window.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
.getInterface(Components.interfaces.nsIWebNavigation)
.QueryInterface(Components.interfaces.nsIDocShellTreeItem)
.rootTreeItem
.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
.getInterface(Components.interfaces.nsIDOMWindow);
var currenturl = mainWindow.getBrowser().selectedBrowser.contentWindow.location.href;
if (currenturl != "about:blank")
{
var currentTitle = mainWindow.getBrowser().selectedBrowser.contentTitle;
var bmsvc = Components.classes["@mozilla.org/browser/nav-bookmarks-service;1"].getService(Components.interfaces.nsINavBookmarksService);
var ios = Components.classes["@mozilla.org/network/io-service;1"].getService(Components.interfaces.nsIIOService);
var uri = ios.newURI(currenturl, null, null);
if (!bmsvc.isBookmarked(uri)) {
bmsvc.insertBookmark(bmsvc.bookmarksMenuFolder, uri, bmsvc.DEFAULT_INDEX, currentTitle);
}
alert("Page bookmarked successfully");
}

}
catch (ee)
{
alert(ee.message);
}
}