Creating/Consuming web service for asp.net, HTML

i have a requirement to build some sort of services that can easily be called to a 3dr party API.

the call can be done through simple 1) HTML page 2) ASPX page 3) MOBILE device

i开发者_开发技巧 need help in what is the best way to go forth.

should i create a separate web service project separately and create few methods [WebMethod] ?

also the method can be static?

 /// <summary>
    /// Summary description for signup_service
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]
    // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
    // [System.Web.Script.Services.ScriptService]
    public class signup_service : System.Web.Services.WebService
    {

        [WebMethod]
        public string CheckZone()
        {
            return "Hello World";
        }
    }

The webmethod cannot be static. Here's why: http://weblogs.asp.net/jasonsalas/archive/2004/02/03/66595.aspx

If you need to interact with the service via AJAX request, you'll need to decorate the webservice with [ScriptService] and/or your webmethods with [ScriptMethod]

The web services have no need to be in their own project, but that architectural decision is based on whatever else you have going on.