…
<asp:TextBox ID="txtUser_Id" runat="server" MaxLength="4" Width="120px" BorderColor="LightSlateGray" BorderWidth="1px"></asp:TextBox>
…
<asp:ImageButton ID="btnInsert" runat="server" ImageUrl="~/Images/Login.GIF" OnClick="btnInsert_Click" />
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<asp:CheckBox ID="cbxRemeberUser" runat="server" Text="記住用戶名" Font-Size="Small" ForeColor="gray"/>
…

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            this.txtUser_Id.Focus();
            if (!Object.Equals(Request.Cookies["UserID"], null))
            {
                //創建一個Cookie對象，實現記住用戶名
                HttpCookie readcookie = Request.Cookies["UserID"];
                this.txtUser_Id.Text = readcookie.Value;
            }
        }
    }
    private void CreateCookie()
    {
        //創建一個Cookie對象
        HttpCookie cookie = new HttpCookie("UserID");
        //判斷Checkbox控件是否被選中
        if (this.cbxRemeberUser.Checked)
        {
            //將用戶編號存儲到創建的Cookie對象中
            cookie.Value = this.txtUser_Id.Text;
        }
        //獲取創建的Cookie對象的過期時間
        cookie.Expires = DateTime.MaxValue;
        //將創建的Cookie對象添加到內部Cookie集合中
        Response.AppendCookie(cookie);
}

    protected void btnInsert_Click(object sender, ImageClickEventArgs e)
    {
…
        if (object.Equals(Request.Cookies["UserID"], null))
        {
          //調用自定義方法 CreateCookie()存儲用戶名
          CreateCookie();
        }
        else
        {
           CreateCookie();
        }
…
}