How can I check how adds are displayed in my application before publishing application in app store?

Question

Hi, I want some information about how the adwirl, mobclix works. How can we test our application by using dummy ads.

I wrote my application using cocos2d.

I did not publish my application in app store still. I registered my application in Mobclix.
I got an id for my application. I want to test how adds display in my application. Is there any way that we can check our application using dummy ads before subting them in app store?

Thank you.