
Listing 1

<%@ Page Language="VB" %>
<%@ Import Namespace="System.Drawing" %>

<Script runat="server">
	sub NameHandler(Sender as Object, e as EventArgs)
		lblMessage.Text = tbName.Text & ", Please choose a color"
	end sub

	sub ListHandler(Sender as Object, e as EventArgs)
		lbColor.BackColor = Color.FromName(Sender.SelectedItem.Text)
	end sub
</Script>

<html>
<body>
	<form name="form1" runat="server">
		<asp:Label ID="lblMessage" runat="server"/><br />
		Name:<asp:TextBox ID="tbName" runat="server" OnTextChanged="NameHandler"
		 AutoPostBack="true" /><br />
		Colors:
			<asp:ListBox ID="lbColor" runat="server"
			 OnSelectedIndexChanged="ListHandler" AutoPostBack="true">
				<asp:ListItem>Red</asp:ListItem>
				<asp:ListItem>Blue</asp:ListItem>
				<asp:ListItem>Green</asp:ListItem>
				<asp:ListItem>BlanchedAlmond</asp:ListItem>
			</asp:ListBox>
	</form>
</body>
</html>

Listing 2

<%@ Control Language="vb" %>
<script runat="server">
	public BackColor as string
	public Username as string
	public Password as string

	sub Login(Sender as Object, e as EventArgs)
		if tbUserName.Text = "user"
			if tbPassword.Text = "pass"
				lblMessage.Text = "Login Successful"
			else
				lblMessage.Text = "Wrong Password"
			end if
		else
			lblMessage.Text = "Wrong Username"
		end if
	end sub
</script>
<table style="background-color:<%=BackColor%>;">
	<tr>
		<td colspan="2" align="center">
			<strong>Login Form</strong>
		</td>
	</tr>
	<tr>
		<td colspan="2" align="center">
			<asp:Label ID="lblMessage" Runat="server" />
		</td>
	</tr>
	<tr>
		<td align="left">Username:</td>
		<td><asp:TextBox ID="tbUsername" Runat="server" /></td>
	</tr>
	<tr>
		<td align="left">Password:</td>
		<td><asp:TextBox ID="tbPassword" TextMode="Password" Runat="server"
		 /></td>
	</tr>
	<tr>
		<td align="center" colspan="2">
			<asp:Button ID="btnLogin" Text="Login" Runat="server" OnClick="Login" />
		</td>
	</tr>
</table>

Listing 3
<%@ Page Language="vb" %>
<%@ Register TagPrefix="Demo" TagName="Login" src="login.ascx" %>

<html>
  <body>

    <form id="Form1" method="post" runat="server">
		<Demo:Login id="login1" BackColor="blue" runat=server />
    </form>

  </body>
</html>

Listing 4

Public Class code_behind
    Inherits System.Web.UI.Page

    Public lblMessage As System.Web.UI.WebControls.Label
    Public tbName As System.Web.UI.WebControls.TextBox
    Public lbColor As System.Web.UI.WebControls.ListBox

    Public Sub NameHandler(ByVal Sender As Object, ByVal e As EventArgs)
        lblMessage.Text = tbName.Text & ", Please choose a color"
    End Sub

    Public Sub ListHandler(ByVal Sender As Object, ByVal e As EventArgs)
        lbColor.BackColor = Color.FromName(Sender.SelectedItem.Text)
    End Sub

End Class

Listing 5
<%@ Page Language="VB" Codebehind='code_behind.aspx.vb' inherits="testApp.code_behind" %>

<html>
<body>
	<form name="form1" runat="server" ID="Form1">
		<asp:Label ID="lblMessage" runat="server"/><br />
		Name:<asp:TextBox ID="tbName" runat="server" OnTextChanged="NameHandler"
		 AutoPostBack="true" /><br />
		Colors:
			<asp:ListBox ID="lbColor" runat="server"
			 OnSelectedIndexChanged="ListHandler" AutoPostBack="true">
				<asp:ListItem>Red</asp:ListItem>
				<asp:ListItem>Blue</asp:ListItem>
				<asp:ListItem>Green</asp:ListItem>
				<asp:ListItem>BlanchedAlmond</asp:ListItem>
			</asp:ListBox>
	</form>
</body>
</html>