Need Help for Creating service to check Pending Transaction?

Hi.

You can use either windows service or web service. But as per your comments to check automatically means windows service is best and it will run all time in your background until you stopped by programatically or  closed. And when you run the windows service if you find any pending then maintain it in db and can show your Pending Transaction in UI. But if you used Web service then it will run when you want to run.

thanks.