MS Captcha with refresh button in asp.net

MS Captcha with refresh button in asp.net

Step 1: Design web from .aspx Page

<form id="form1" runat="server">

    <div>

        <asp:ScriptManager ID="sm" runat="server">

        </asp:ScriptManager>

        <asp:UpdatePanel ID="up1" runat="server">

            <ContentTemplate>

                <cc1:CaptchaControl ID="Captcha1" runat="server" CaptchaBackgroundNoise="Low" CaptchaLength="6"

                    CaptchaHeight="80" CaptchaWidth="350" CaptchaLineNoise="None" CaptchaMinTimeout="5"

                    CaptchaMaxTimeout="240" FontColor="CadetBlue" />

                <asp:LinkButton ID="lnkrefresh" runat="server" OnClick="_Click" Text="Refresh" CausesValidation="false"> </asp:LinkButton>

            </ContentTemplate>

        </asp:UpdatePanel>

    </div>

    <asp:TextBox ID="txtCaptcha" runat="server" Width="350px"></asp:TextBox>

    <br />

    <asp:Button ID="btn" runat="server" Text="Check" OnClick="btn_Click" BackColor="YellowGreen" />

    <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="*Required"

        ControlToValidate="txtCaptcha"></asp:RequiredFieldValidator>

    <br />

    <br />

    <asp:Label ID="lblmsg" runat="server" Font-Names="Arial" Text=""></asp:Label>

    </form>

Step 2: Logic on .Cs page.

protected void btn_Click(object sender, EventArgs e)

    {

        Captcha1.ValidateCaptcha(txtCaptcha.Text.Trim());

        if (Captcha1.UserValidated)

        {

            lblmsg.ForeColor = System.Drawing.Color.Green;

            lblmsg.Text = "Sucess";

        }

        else

        {

            lblmsg.ForeColor = System.Drawing.Color.Red;

            lblmsg.Text = "Fail";

        }

    }

    protected void _Click(object sender, EventArgs e)

    { }

It Will Look like :-