Hi, To all sitepoint masters,… i saw some other website using captha for validating or putting extra security before the user can login into their website…I just what to know how can i achieve like this,i want also to put captha image but i don’t know what is the logic behind on it.I hope some one will help me on this.
Captchas are intended to stop spam bots misusing your contact form (for example).
I don’t see any advantage to using them on a user login.
They are fairly simple to implement, normally using third party code or a third party service.
Here is a list of some which are freely available: http://woork.blogspot.de/2009/02/10-free-captcha-scripts-and-services.html
However, captchas present a big usability barrier for many users, so please think carefully before using them.
Hi pullo, Thank you so much for the reply,…is this needed to have a capthca? where should i put captcha if this is not needed in the log-in form?..thank you in advance.
Captchas are a mechanism to prevent bots submitting contact forms and flooding your inbox with spam.
AFAIK a captcha would be quite pointless in a login form.
Have a look at this thread where (especially towards the end) captchas and their alternatives are discussed at some length: