Tim's Loopy Control Structures [http://nefariousdesigns.co.uk/archive/2006/05/loopy/] is an in-depth post detailing the ins and outs of programming control structures. Makes good follow up reading as to my recent getElementsByClassName script [https://muffinresearch.co.uk/archives/2006/04/29/getelementsbyclassname-deluxe-edition/]. Tim was one