Ajax Asynchronous call (VB.NET)

1. declare param type for passing the parameters

Public Class GetRiskParams
    Public RISKACCPRIV As String
    Public RISKACCCONF As String
    Public RISKACCFRAU As String
    Public RISKACCAVAI As String
    Public RISKACCTPA As String
    Public RISKACCDISA As String
    Public RISKACCFINA As String
    Public RISKACCREGU As String
End Class

2. create a web method in a web service

Public Class MyWebService
    Inherits System.Web.Services.WebService

    Public Function GetMaxRisk(ByVal params As GetRiskParams) As String
        Dim maxRisk As String = String.Empty
        Using conn As New SqlConnection(ConfigurationManager.ConnectionStrings.Item("MyConnectionString").ToString())
            Dim qryString As String = String.Format("select dbo.GetMaxRisk('{0}', '{1}', '{2}', '{3}', '{4}', '{5}', '{6}', '{7}')", _
                                                    params.RISKACCCONF, params.RISKACCFRAU, params.RISKACCAVAI, params.RISKACCTPA, params.RISKACCDISA, params.RISKACCFINA, params.RISKACCREGU, params.RISKACCPRIV)
            Using cmd As New SqlCommand(qryString, conn)
                conn.Open()
                maxRisk = cmd.ExecuteScalar()
            End Using
        End Using
        Return maxRisk
    End Function


 Public Function IsAppNameDuplicated(ByVal appKey As String, ByVal appName As String) As String
  Return "abc"
 End Function
End Class

3. calling the web method from javascript client code

function OnChangeRisks() {
    var params = new GetRiskParams();
    params.RISKACCPRIV = comboRiskPrivacy.GetValue();
    params.RISKACCCONF = comboRiskConfidentiality.GetValue();
    params.RISKACCFRAU = comboRiskFraud.GetValue();
    params.RISKACCAVAI = comboRiskAvailability.GetValue();
    params.RISKACCTPA = comboRisk3rdParty.GetValue();
    params.RISKACCDISA = comboRiskDisaster.GetValue();
    params.RISKACCFINA = comboRiskFinancialReporting.GetValue();
    params.RISKACCREGU = comboRiskRegulatoryCompliance.GetValue();

    AssetManagementWebService.GetMaxRisk(params, DisplayMaxRisk, OnTimeout);
}

function DisplayMaxRisk(result) {
    clientHighestOverallTextBox.SetText(result);
}

function OnTimeout() {
}