Authorize.net payment gateway integration in C#

1. Which payment gateway you want to use? There are many available

2. What type of payment you want to have

i'm using authorize.net, i'm integrate with the help of this link"http://www.keithfimreite.com/Authorize-Net.aspx"

but the error comes"

Refer here

https://support.authorize.net/authkb/index?page=content&id=A597&actp=LIST

but in this link they don't tell about how set up account and i'm not using market type so how can i pass the value

Thank's

Anju Srivastava

You can download sample code form here

http://developer.authorize.net/downloads/samplecode