How to populate textboxes using dropdownlist

Hi,
i am using asp.net and i am trying to autopopulate 4 textboxes using a dropdownlist such that when i select an item from dropdownlist all the 4 textboxes should auto fill. can anyone plz help me this is the following code that i have done....
Code

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="dailyentry.aspx.vb" Inherits="_Default" Strict="true" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SQLClient" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace ="AjaxControlToolkit" TagPrefix ="cc1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
 &n ...