I am not good at HTML or any other coding language but I got excellent marketing and SEO skills. Last month I joined adsense and I am doing good, but one thing which is giving me nightmares is putting adsense codes. Some codes work fine but when I put some codes a white space appears in place of ads. I tried to fix it but googling the query but still the problem persists. If anyone of you guys can sail me through this or can tell me why these white spaces appear in place of ads.
May be you are placing more than three ad slots in a single page, follow this article to see how to place adsense ads. Note: if you refer your url here so that we can help you.
Yes there is a limit to the number of adsense blocks in a page. Also it could be that adsense doesn't yet have any ad to display in the first, second or third block. This you can't do much about and you shouldn't worry about it, not everyone sees the same ads anyway so what you see is not what other will see, perhaps there will be ads for them and not for you, or the way around. So don't worry, only take care of putting no more than 3 adsense blocks, 3 link units blocks and 2 adsense for search boxes on a same page.
if you make a blog blogger is not allowed more than 3 adds a page so this is a problem you want to paste more and more adds on your blog and adds not show
Search in YouTube for the tutorial "How to insert Adsense Code in Article or any thing like this". Hope you will get some good tutorial there. That is a large storage of useful video.
A free version of my software creates the Adsense HTML needed for ad units - with colors matched to any web page. But, as already mentioned Google only allow 3 ad units per page and you need relevant keywords on your site to let them decide which relevant ads to serve