JSON Retrieval Speed

 Hi all

I m using the following codes to populate HTML table,

<WebMethod()> _
    Public Function SrcTblReg(ByVal SrchTxt As String, ByVal FnameSrctxt As String, _
                                  ByVal SnameSrctxt As String, ByVal TnameSrctxt As String, _
                                  ByVal LnameSrctxt As String, ByVal TelSrcTxt As String, _
                                  ByVal SSNSrcTxt As String, ByVal EmailSrctxt As String, _
                                  ByVal DOBSrcTxt As String)
        Dim constr As String = ConfigurationManager.ConnectionStrings("ARTSQLConStrng").ConnectionString
        Using con As New SqlConnection(constr)
            Using cmd As New SqlCommand("TblRegSearch", con)
                cmd.CommandType = CommandType.StoredProcedure
                If (String.IsNullOrEmpty(SrchTxt)) Then
                    cmd.Parameters.Add("@Searchtxt", SqlDbType.NVarChar).Value = DBNull.Value
                Else
                    cmd.Parameters.Add("@Searchtxt", SqlDbType.NVarChar).Value = SrchTxt.Trim()
                End If
                If (String.IsNullOrEmpty(FnameSrctxt)) Then
                    cmd.Parameters.Add("@Fname", SqlDbType.Int).Value = DBNull.Value
                Else
                    cmd.Parameters.Add("@Fname", SqlDbType.NVarChar).Value = FnameSrctxt
                End If
                If (String.IsNullOrEmpty(SnameSrctxt)) Then
                    cmd.Parameters.Add("@Sname", SqlDbType.Int).Value = DBNull.Value
                Else
                    cmd.Parameters.Add("@Sname", SqlDbType.NVarChar).Value = SnameSrctxt
                End If
                If (String.IsNullOrEmpty(TnameSrctxt)) Then
                    cmd.Parameters.Add("@Tname", SqlDbType.Int).Value = DBNull.Value
                Else
                    cmd.Parameters.Add("@Tname", SqlDbType.NVarChar).Value = TnameSrctxt
                End If
                If (String.IsNullOrEmpty(LnameSrctxt)) Then
                    cmd.Parameters.Add("@Lname", SqlDbType.Int).Value = DBNull.Value
                Else
                    cmd.Parameters.Add("@Lname", SqlDbType.NVarChar).Value = LnameSrctxt
                End If
                If (String.IsNullOrEmpty(TelSrcTxt)) Then
                    cmd.Parameters.Add("@TelMob", SqlDbType.Int).Value = DBNull.Value
                Else
                    cmd.Parameters.Add("@TelMob", SqlDbType.NVarChar).Value = TelSrcTxt
                End If
                If (String.IsNullOrEmpty(SSNSrcTxt)) Then
                    cmd.Parameters.Add("@SSnum", SqlDbType.Int).Value = DBNull.Value
                Else
                    cmd.Parameters.Add("@SSnum", SqlDbType.NVarChar).Value = SSNSrcTxt
                End If
                If (String.IsNullOrEmpty(EmailSrctxt)) Then
                    cmd.Parameters.Add("@Email", SqlDbType.Int).Value = DBNull.Value
                Else
                    cmd.Parameters.Add("@Email", SqlDbType.NVarChar).Value = EmailSrctxt
                End If
                If (String.IsNullOrEmpty(DOBSrcTxt)) Then
                    cmd.Parameters.Add("@DOB", SqlDbType.Date).Value = DBNull.Value
                Else
                    Dim DOBDte As DateTime = String.Format("{0:dd-MMMM-yyyy}", DOBSrcTxt)
                    cmd.Parameters.Add("@DOB", SqlDbType.Date).Value = DOBDte
                End If
                cmd.Connection = con
                    Dim ds As New DataSet()
                    Using sda As New SqlDataAdapter(cmd)
                        sda.Fill(ds, "TblRegSrc")
                    End Using
                    Return ds.GetXml()
                End Using
            End Using
    End Function

function srctbl() {$(function () {
                var obj = {};

                obj.SrchTxt = $('#srctxt').val()
                obj.FnameSrctxt =$('#fnamesrc').val()
                obj.SnameSrctxt = $('#snamesrc').val()
                obj.TnameSrctxt = $('#tnamesrc').val()
                obj.LnameSrctxt = $('#lnamesrc').val()
                obj.TelSrcTxt = $('#telsrc').val()
                obj.SSNSrcTxt = $('#ssnsrc').val()
                obj.EmailSrctxt = $('#emailsrc').val()
                obj.DOBSrcTxt = $('#dobsrc').val()$.ajax({
                    type: "POST",
                    url: "../CONFIG/WebSerTblsSearch.asmx/SrcTblReg",
                    data: JSON.stringify(obj),
                    contentType: "application/json; charset=utf-8",
                    dataType: "json",
                    success: OnSuccess2,
                    failure: function (response) {
                        alert('f' + response.d);
                    },
                    error: function (response) {
                        alert('E' + response.d);
                    }
                });
            });

            function OnSuccess2(response) {
                var xmlDoc = $.parseXML(response.d);
                var xml = $(xmlDoc);
                var customers = xml.find("TblRegSrc");
                var row = $("[id*=RegSrc] > tbody tr:last-child").clone(true);$("[id*=RegSrc] tr").not(':has(th)').remove();$.each(customers, function () {$("#ptfn", row).html($(this).find("Column1").text());$("#ptname", row).html($(this).find("FullName").text());$("#ptdob", row).html($(this).find("DOB").text());$("[id*=RegSrc]").append(row);
                    row = $("[id*=RegSrc] > tbody tr:last-child").clone(true);
                })
            }
        }

The code performs search in a table, whenever I get more than 500 rows, the speed in data retrieval drops drastically, the table takes a long time to populate.

any idea how to speed the process up?

thanks