I want to write a full article about this issue but I don't have the time at the moment. Regardless, this is a very common mistake that I see on Lush that needs to be addressed.
Too many people improperly interchange "lay" and "lie" (and their respective parts). The following article sums up their difference. READ IT!
http://www.grammarmudge.cityslide.com/articles/article/992333/8992.htm

