There is no additional hosting or costs. You just need an alphanumeric receiver (cellphone, pager) and there is no special service. You just use what you have. It runs on Windows and Unix servers and it is ASP-based. You can write me at scep_99@yahoo.com. Any server that can run ASP can run this script. Please check your cellphone provider however some charge a quarter to fifty cents for text messaging. Most people assume this is free. It isn't always.
Once you buy it. You install it on your website. Insert your phone # where mine currently is, and that's it. Your users register and your pager/cellphone goes off. You call them back-its that easy!