admin:
-create a category
-edit a category
*check for cyclic links
-delete a folder

-create a new ad (Image and HTML)
-edit the ad
-delete the ad

user:
-create two ads(in admin)
-refresh page (each ad should appear after another)
-create new ad(in admin)
-refresh page (new ad shoudl appear)

-click on ad
*check stats in admin