If you have the same amount of traffic but the clicks have reduced, you should try to change the ad placement. You can also try to add fresh content regularly. However, if you provide more details, someone can help you in a better manner.
Then, you shall first find out what is the rootcause. After that, make some corrective action to solve it
Need more information, how large is the drop? Why isn't many people clicking on your ads. Have you changed the format of your site? Are you experimenting with ad placement?
I always have noticed the drop, not only in clicks, but as well as the money I receive. Yet I believe that this is pretty much normal due to the financial crisis they say we are experiencing.. Last year, I was earning almost 30-40 $ per day, but the last months I got mostly about 15-20 $.. Hope soon there will be an increase.