create a string image

[cocoll]

hello!
if we sign up at a hotmail account or other account we see before submit our information that we must enter a words and that is for prevent "robots" to sign up with hundreds of accounts.
so this characters is an image,so what i want is your help in this:
i want to create this image so what i know is this:
i can generate random characters it's not so difficult and i can build a string from them ,then i can create an image with that string but i can give the string the format that we can see at sign up at any account so i tried to play with "font-family" with no success so i need your help in this and if you can tell me the difference in asp.net=create this image,because i used vb.net with a pictureBox.
thank you very much.

[dnanetwork]

http://www.c-sharpcorner.com/UploadFile/oguzaltuncu/TextToImageGen08012005023259AM/TextToImageGen.aspx

http://knowlegezone.com/documents/80/Simple-ASPNET-CAPTCHA-Tutorial/

hope that helps.

besides there is a free option and very much handy.

no need to write much code, few settings and you are ready to go

search for Re-Captcha.

[cocoll]

thank you for your reply.
first the 2 links are useful,and re-captcha is what i need but not like an application because i don't have a website so i want to build something like that,so just i need to know how can i give that form to the string image.
thank you very much.

[dnanetwork]

if problem is resolved then mark your thread as resolved.