how to use capcha code in the asp.net

how i can add capcha code in the asp.net reg开发者_开发百科istration form

There is a helper in web matrix.

http://www.dotnetcurry.com/ShowArticle.aspx?ID=611

There is a captcha control sample on Code project for asp.net 1.1 and 2.0

And on codeplex there is one for .net 3.5 - MyCaptcha is a free opensoruce ASP.NET Captcha control written in C# 3.0.

Googles ReCaptcha is pretty neat and very popular. Lot's of examples to get up and running quickly.

Have a look at using reCAPTCHA with ASP.NET

this will help you

http://viralsarvaiya.wordpress.com/2010/11/22/arithmetic-captcha-in-asp-net/

http://viralsarvaiya.wordpress.com/2009/07/08/how-to-generate-captcha-image-in-asp-net/