howto create and call json webservice in asp.net example

1.Add to webservice method this tag System.Web.Script.Services.ScriptService(),
so it will be looking like this:

Imports System.Web.Services
Imports System.Web.Services.Protocols
Imports System.Web.Script.Services
Imports WebControlLibrary
Imports Ubill.Business
Imports System.ComponentModel

<System.Web.Services.WebService(Namespace:="http://tempuri.org/")> _
<System.Web.Services.WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _
<ToolboxItem(False)> <System.Web.Script.Services.ScriptService()> _
Public Class AtlasHub
    Inherits System.Web.Services.WebService


    <WebMethod(True)> _
    Public Function AdvanceCustomerDelete(ByVal CustomerID As String) As String
 Return cachefactory.AdvanceCustomerDelete(CustomerID)
    End Function

End Class

2.On aspx page add this script manager binding :

<asp:ScriptManager runat="server" ID="scriptManagerId">
 <Scripts>
     <asp:ScriptReference Path="~/common/AtlasHub.js" />
 </Scripts>
 <Services>
     <asp:ServiceReference  Path="~/common/AtlasHub.asmx " />
 </Services>
</asp:ScriptManager>

3.AtlasHub.js is javascript file those contains maintenance functions:

// Business functions 
// // -------------------------------------------  
function AdvanceCustomerDelete( customerID , onSuccessAdvanceCustomerDelete){
 YouBillWeb.AtlasHub.AdvanceCustomerDelete(customerID,onSuccessAdvanceCustomerDelete,onTimeOut,onFailed);
}

// Maintenance functions 
// -------------------------------------------  
// This is the callback function invoked if the Web service
// succeeded.
// It accepts the result object, the user context, and the 
// calling method name as parameters.
function OnSucceededWithContext(result, userContext, methodName)
{
    var output;

    // Page element to display feedback.
    var RsltElem = document.getElementById("ResultId");

    var readResult;
    if (userContext == "XmlDocument")
    {

 if (document.all)
     readResult =
  result.documentElement.firstChild.text;
 else
     // Firefox
    readResult =
  result.documentElement.firstChild.textContent;

  RsltElem.innerHTML = "XmlDocument content: " + readResult;
    }

}

// This is the callback function invoked if the Web service
// succeeded.
// It accepts the result object as a parameter.
function onSuccess(result, eventArgs)
{
    // Page element to display feedback.
    var RsltElem = document.getElementById("ResultId");
    RsltElem.innerHTML = result;
}

function OnSucceeded(result, eventArgs)
{
    // Page element to display feedback.
    var RsltElem = document.getElementById("ResultId");
    RsltElem.innerHTML = result;
}


// This is the callback function invoked if the Web service
// failed.
// It accepts the error object as a parameter.
function onFailed(error)
{
    // Display the error.    
    var RsltElem = document.getElementById("ResultId");
    RsltElem.innerHTML =
    "Service Error: " + error.get_message();
}

function onTimeOut(error)
{
    // Display the error.    
    var RsltElem = document.getElementById("ResultId");
    RsltElem.innerHTML =
    "Service Error: " + error.get_message();
}

if (typeof(Sys) !== "undefined") Sys.Application.notifyScriptLoaded();

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