Very easy, use any captcha service providers or any other else created on your own using GDLibrary in PHP
One of the most famous Captcha service providers is recaptcha.net http://recaptcha.net/plugins/php/ And some more are www.PHPCaptcha.org www.captchacreator.com But I will suggest you a very simple one here. You are left to discuss on security issues in this type. Steps: a) First select a random number/character/symbols, etc whatever you think you should use in you captcha b) Use a session variable to store the sequence you have generated c) Use GDLibrary extension of PHP to generate an image out of the text you have generated d) Display the image somewhere and read a text input e) When the form is submitted, match the input with the session variable you had stored in step 'b'. This is a simple method how to stop spams. However you can do another trick too, if you do not have a proper knowledge in GD a) Randomize number. b) have 0-9 digits' images. c)Break the characters into digits and display the image sequences to build an image of number. But make sure that the names of images are some encrypted strings so that pattern of the next digit cannot be guessed. Otherwise robots just break the code and input what you are expecting. For more you can continue the discussion Thanks --~--~---------~--~----~------------~-------~--~----~ FOSS Nepal mailing list: [email protected] http://groups.google.com/group/foss-nepal To unsubscribe, e-mail: [EMAIL PROTECTED] Community website: http://www.fossnepal.org/ -~----------~----~----~----~------~----~------~--~---
