Spambot Form Entry Prevention using CSS & Coldfusion 4.5

[karmatech]

Hello,

I have an html form using a coldfusion post script. I want to create a hidden field using CSS which only spambots will see. Then I need some coldfusion code to tell the form not to submit entries with that field filled in. Is there a good tutorial or site someone knows to explain this for me.

Many Thanks

JD

[Daverms]

Hi,

You mean putting 'CAPTCHA' like thing in your page to prevent the SPAM Bots?...

[karmatech]

well a CAPTCHA is good but i don't want to give my users more reason not to fill in my form, so a hidden form field that a spambot would naturally fill in without realising is my best bet. any ideas?

[Daverms]

Then add a piece of javascript to check whether the hidden field is filled in with any value or not, and submit the form only if its empty..

[karmatech]

do you have an example of some code, i'm not that skilled in javascript. thanks

[Daverms]

like this,

function fnValidate()
{
if (document.your_form_name.hidden_field_name.value=='')
{
document.your_form_name.action='your_actionpage.cfm';
document.your_form_name.submit();
}
}

and call this function in your <form> tag's onSubmit event like this,

<form name="your_form_name" method="post" onSubmit="return fnValidate();">

[karmatech]

hi, thanks for that, i think its worked, fingers crossed for the results and those pesky spambots stop annoying me 🙂

[karmatech]

ok slight problem, whilst the code you gave me was very helpful it seems i need a different fix :

I don't want the spambots to not actually process the form entry, i wish to recieve it but just to a new address spam@hostname.com. By telling the form to process to a new your_actionpage.cfm isn't 100% there. The mail action is obviously controlled by the aplication.cfm which currently can only send to one mailserver. Is there an if comment i can put in the application.cfm which selects variables to send to a different address?

I hope this makes sense. thanks

[Daverms]

Hi,

Then put some conditions in your <form> tag just infront of the "action" attribute..
For eg.,

[Guest]

I do it a different way. I create an authorization key that I pass in a hidden form field and save as a session variable. Then upon form submission I check to see if the session auth key matches the form auth key. if not I bounce them somewhere.