Problem to do a roaming network with 2 Airport Extreme

Hello,

I try to extend my wireless on my Airport Extreme. So, I buy another Airport Extreme and do the roaming network as this article:

http://support.apple.com/kb/HT4260

I do every steps except 3rd step.

but it's not work.

When I check with Airport Utility, I got the error that my second Airport Extreme cannot find the Wireless Network Name of the first one as show on the picture below: