NATS can protect some pages with CAPTCHAs, providing an additional security measure that helps to prevent against automated login attempts.
To use the Captcha feature, insert the following somewhere between the <FORM> and </FORM tags on the desired form template:
Note: this code is for using your own Captcha and not using the NATS4 Captcha
<img src="{$image_url}" > //this will make the captcha image
<input type="text" name="signup[captcha:1]" value="{$vars.captcha}"> // this is where the users will type in what they see in the Captcha box
{if $errors.captcha}{$errors.captcha}{/if} //if there any errors when the users typed in what they saw in the Captcha box, this will display the errors
{if $captcha_key}<input type="hidden" name="signup[captcha_key]" value="{$captcha_key}">{/if} // if present, add the additional captcha key into the form as a hidden field
A more stylized example is shown below:
<fieldset>
<legend>Captcha Image</legend>
<div class="form_input">
<center><img src="{$image_url}" width="150" height="45" border="0" style="padding: 3px; padding-left: 10px; padding-top: 6px"></center>
</div>
<div class="form_input">
{if $errors.captcha}<div class="join_error">{$errors.captcha}</div>{/if}
<label class="memberinfo">Verify Text:</label>
<input type="text" class="signup_input" name="signup[captcha:1]" size="35" value="{$vars.captcha}">
</div>
{if $captcha_key}
<input type="hidden" name="signup[captcha_key]" value="{$captcha_key}">
{/if}
</fieldset>
If your CAPTCHA image is missing from a page, ensure your server has both GD and FreeType installed, and that GD was compiled with FreeType support. Also, make sure the CAPTCHA is enabled on the template.
For more information on CAPTCHA images and how to add them in NATS4, please see our NATS4 Adding a Verification Image wiki article.
See Also
- CAPTCHA -- Wikipedia's CAPTCHA article
