Access Denied On window.Load Javascript function
12/17/2013
Kept on getting an "access denied" error while loading a page in 15 hive ( _Layouts" folder.) I was using "window.load" javascript function to open this page in full page mode. The solution was to refer to this page with the full url aka http://SiteCollectionUrl/_layouts/pageName.aspx and not a relative url like "_layouts/pageName.aspx"
Don't know exactly the reason but my guess is that it has something to do with cross site scripting. Anyways hope this helps you
cheers