if facebook app is not installed then it should open in browser

I am trying to open facebook page when user click on imageview..but if app is installed then it works fine,but what i want is if app is not installed then it should open in browswer,,following is my code..

   iv_fb.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {


            boolean installed = appInstalledOrNot("fb://page/pageid");  
            if(installed) {
                //This intent will help you to launch if the package is already installed
               /* Intent LaunchIntent = getPackageManager()
                    .getLaunchIntentForPackage("com.facebook.katana");*/

                startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("fb://page/pageid")));
                ContactActivity.this.finish();
               // startActivity(LaunchIntent);

                System.out.println("App is already installed on your phone");         
            } else {
                System.out.println("App is not currently installed on your phone");
            }

            // TODO Auto-generated method stub

        }
    });

    private boolean appInstalledOrNot(String uri) {
    PackageManager pm = getPackageManager();
    boolean app_installed;
    try {
        pm.getPackageInfo(uri, PackageManager.GET_ACTIVITIES);
        app_installed = true;
    }
    catch (PackageManager.NameNotFoundException e) {
        app_installed = false;
    }
    return app_installed;
}