Want Webservices in json

Yes, you can do. It needs lots of modification to achieve the same. So better to use different actions for different purpose.

 

http://stackoverflow.com/questions/9569270/custom-method-names-in-asp-net-web-api

is this possible for creating a single function for all

You can create a WebApi which works as RESTful service. WebApi works only HTTP methods like GET, PUT, POST, DELETE etc..You need to call the WebAPI from your application. Follow below link that will help you:

 

https://www.asp.net/web-api/overview/getting-started-with-aspnet-web-api/tutorial-your-first-web-api

 

 http://www.c-sharpcorner.com/uploadfile/3d39b4/getting-started-with-asp-net-web-api/