Add Banners

I am planning to run advertisements from my site but my site is not database driven. Is there any way that companies can watch the status of their banners. I can probably show them the server logs but it is hard to keep track of that way and they might think that I have edited the picture to show them that they are getting more results. I don’t want to lie or anything and that is why I was wondering if there is any software that I can embed on my server so that the manufacturers will be able to watch the stats of their banners.

I can password protect a page with Javascript. I know this is not the best method but these are only stats and there is no private information stored on them. I am planning to charge the manufacturers per 1000 impressions. So if there is a code that I use in the banner and then display the results in .html format, that would be great. Thanks a lot.