Maintain the data on postback without using database using jquery

Here it is,

HTML

<asp:GridView ID="gvCustomers" CssClass = "table" runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:TemplateField HeaderText="Name" ItemStyle-Width="150px" ItemStyle-CssClass="Name">
            <ItemTemplate>
                <%# Eval("Name") %>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Country" ItemStyle-Width="150px" ItemStyle-CssClass="Country">
            <ItemTemplate>
                <%# Eval("Country")%>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>
<br />
<table border="0" cellpadding="0" cellspacing="0">
    <tr>
        <td style="width: 150px">
            Name:<br />
            <asp:TextBox ID="txtName" runat="server" Width="140" Text="" />
        </td>
        <td style="width: 150px">
            Country:<br />
            <asp:TextBox ID="txtCountry" runat="server" Width="140" Text="" />
        </td>
        <td style="width: 100px">
            <br />
            <asp:Button ID="btnAdd" runat="server" Text="Add" />
        </td>
    </tr>
</table>
<br />
<asp:Button Text="Reload" runat="server"  />

 VB.Net

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.BindGrid()
    End If
End Sub

Private Sub BindGrid()
	Dim dt As New DataTable()
	dt.Columns.AddRange(New DataColumn() {New DataColumn("Name", GetType(System.String)), New DataColumn("Country", GetType(System.String))})
        
	If (dt.Rows.Count = 0) Then
		dt.Rows.Add()
	End If

gvCustomers.DataSource = dt
    gvCustomers.DataBind()
 End Sub

 JavaScript

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript">
$(function () {
    $("[id*=btnAdd]").click(function () {
        //Reference the GridView.
        var gridView = $("[id*=gvCustomers]");
 
        //Reference the first row.
        var row = gridView.find("tr").eq(1);
 
        //Check if row is dummy, if yes then remove.
        if ($.trim(row.find("td").eq(0).html()) == "") {
            row.remove();
        }
 
        //Clone the reference first row.
        row = row.clone(true);
 
        //Add the Name value to first cell.
        var txtName = $("[id*=txtName]");
        SetValue(row, 0, "name", txtName);
 
        //Add the Country value to second cell.
        var txtCountry = $("[id*=txtCountry]");
        SetValue(row, 1, "country", txtCountry);
 
        //Add the row to the GridView.
        gridView.append(row);
 
        return false;
    });
 
    function SetValue(row, index, name, textbox) {
        //Reference the Cell and set the value.
        row.find("td").eq(index).html(textbox.val());
 
        //Create and add a Hidden Field to send value to server.
        var input = $("<input type = 'hidden' />");
        input.prop("name", name);
        input.val(textbox.val());
        row.find("td").eq(index).append(input);
 
        //Clear the TextBox.
        textbox.val("");
    }
});
</script>

In short I just removed the SELECT and INSERT Statement

I dont know how to save it in JAVASCRIPT Side

I think you used this code to save it int JAVASCRIPT

protected string Values;

But I don't know how to use, thanks