Creating web service in VB.NET that outputs to JSON raw data

Here is a quick tutorial on creating a web service in VB.NET that output the data in JSON.
Imports System
Imports System.Web
Imports System.Collections
Imports System.Web.Services
Imports System.Web.Services.Protocols
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.Script.Serialization
Imports System.Web.Script.Services
Imports System.ComponentModel
<System.Web.Services.WebService(Namespace:="")> _
<System.Web.Services.WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _
<ToolboxItem(False)> _
Public Class config
    Inherits System.Web.Services.WebService
    <WebMethod()> _
    <ScriptMethod(ResponseFormat:=ResponseFormat.Json)> _
    Public Function getConfigurationValueByKey(ByVal strKeyName As String) As String
        Dim sqlConnection As SqlConnection = New SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings("ConnStr").ConnectionString)
        Dim sqlCommand As SqlCommand = New SqlCommand("SELECT * FROM table1 WHERE column1 ='" + strKeyName + "';", sqlConnection)
        Dim sqlDataset As DataSet = New DataSet()
        Dim sqlDataAdapter As SqlDataAdapter = New SqlDataAdapter(sqlCommand)
        Dim MArray()() As String = New String(sqlDataset.Tables(0).Rows.Count)() {}
        Dim i As Integer = 0
        For Each rs As DataRow In sqlDataset.Tables(0).Rows
            MArray(i) = New String() {rs("KeyName").ToString(), rs("ValueName").ToString()}
            i = i + 1
        Dim js As JavaScriptSerializer = New JavaScriptSerializer()
        Dim sJSON As String = js.Serialize(MArray)
        Return sJSON
    End Function
End Class
Output will be something like this.
  <?xml version="1.0" encoding="utf-8" ?> 
  <string xmlns="">[["key1","value1"],["key2","value2"]]</string>