problems of captcha

Question

what is the cptCaptcha I use this code for captcha

 

 

 

protected void btnVerify_Click(object sender, EventArgs e)

{

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

if (cptCaptcha.UserValidated)

{

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

lblErrorMessage.Text = "Valid text";

}

else

{

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

lblErrorMessage.Text = "InValid Text";

}

}