i placed 1, Wide Skyscraper (160x600) 1, Large Rectangle (336 x 280) 1, (200x90_4) Displays up to 4 links 1 Search box is it ok? search box counts as an ad unit?
can i do this 1, Wide Skyscraper (160x600) 1, Large Rectangle (336 x 280) 1, (200x90_4) Displays up to 4 links 1 Search box 2 referral
Depends on where you placed them. Try placing the rectangule floating left inside the content, since we read from left to right, it has more probabilities to be seen. The skyscrapper at the right of the content for when people finish reading one line they will see it, and your link unit over before the content.
This is directly from the Google Adsense Policies Up to three ad units may be displayed on each page. A maximum of two Google AdSense for search boxes may be placed on a page. A single link unit may also be placed on each page. Up to two referral units from each referral product or offering may be displayed on a page, in addition to the ad units, search boxes, and link units specified above.