Here is my HTML
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "
<html xmlns="
>
<head id="Head1" runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<asp

anel ID="Panel1" runat="server" Height="50px" Width="125px">
<fieldset><legend><span>Customer 1 Personal Details</span></legend>
<asp:Label ID="Label1" runat="server" AssociatedControlID="TextBox1" Text="Label 1"><asp:TextBox ID="TextBox1" runat="server"></asp:TextBox><asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="RequiredFieldValidator" ControlToValidate="textbox1" EnableClientScript="false"></asp:RequiredFieldValidator><asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" ErrorMessage="RegularExpressionValidator" enableclientscript="true" ControlToValidate="textbox1" ValidationExpression="^[a-zA-Z ]*$"></asp:RegularExpressionValidator></asp:Label>
<asp:Label ID="LabelTextBox2" runat="server" AssociatedControlID="TextBox2" Text="Label 2"><asp:TextBox ID="TextBox2" runat="server"></asp:TextBox></asp:Label>
<asp:Label ID="Label3" runat="server" AssociatedControlID="TextBox3" Text="Label 3"><asp:TextBox ID="TextBox3" runat="server"></asp:TextBox><asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ErrorMessage="RequiredFieldValidator" ControlToValidate="textbox3" EnableClientScript="false"></asp:RequiredFieldValidator><asp:RegularExpressionValidator ID="RegularExpressionValidator3" runat="server" ErrorMessage="RegularExpressionValidator" enableclientscript="False" ControlToValidate="textbox3" ValidationExpression="^[a-zA-Z ]*$"></asp:RegularExpressionValidator></asp:Label>
</fieldset>
</asp

anel>
<asp

anel ID="Panel2" runat="server" Height="50px" Width="125px">
<fieldset><legend><span>Customer 1 Personal Details</span></legend>
<asp:Label ID="Label4" runat="server" AssociatedControlID="TextBox4" Text="Label 4"><asp:TextBox ID="TextBox4" runat="server"></asp:TextBox></asp:Label>
<asp:Label ID="Label5" runat="server" AssociatedControlID="TextBox5" Text="Label 5"><asp:TextBox ID="TextBox5" runat="server"></asp:TextBox></asp:Label>
<asp:Label ID="Label6" runat="server" AssociatedControlID="TextBox6" Text="Label 6"><asp:TextBox ID="TextBox6" runat="server"></asp:TextBox></asp:Label>
</fieldset>
</asp

anel>
<asp:Button ID="Button1" runat="server" Text="Button" />
</form>
</body>
</html>
and this is my page load event
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Page.IsPostBack Then
TextBox2.Visible = True
LabelTextBox2.Visible = True
Else
TextBox2.Visible = False
LabelTextBox2.Visible = False
End If
End Sub