Web Service required for existing Website

We run a SMS text message website. Currently, the system works like this. A user can register on the site and then create contacts (firstname, lastname, mobile number) and they can also create groups (groupid, groupname) and then link users to the groups. They can then chopose to sent SMS messages to a single user or group. We need to have a webservice or similar that will accept information from 3rd party websites and create a contact record and assign it to a group(s) Someone signs up on a 3rd party site and their details can be passed to our site and are assigned to a group (already specified) The 3rd party site will be hardcoded by thier web designers - but I would need some example code to offer them to help. The webservice will run on our site which is ASP but the server is .NET enabled. All info is stored in the SQL backend. It will need to have the ability to check authentication details (from the DB) of data submitted and post the contact and group information into the DB. From there, the company would send the text message to the group through our site in the normal way. So to summerise, we require a Web Service that will input data into a database with user authentication ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Windows 2003 Server with .NET