Anantprakash Pathak thinks this is interesting: you must always use var to declare local variables. From Variable Scope from JavaScript: The Definitive Guide, 6th Edition by David Flanagan Publisher: O'Reilly Media, Inc. Released: May 2011 Note ** If you don't make variables in a Fun as var they will be declared as global variables. Share this highlight http://www.safaribooksonline.com/a/javascript-the-definitive/10944004/ Twitter Facebook Google Plus Email Get Instant Access Now Start a Free Trial Have an account? Sign in. Minimise Unlock the rest of JavaScript: The Definitive Guide, 6th Edition and 30,000 other books and videos By clicking this box, you confirm that you have read and agree to the terms and conditions of our Membership Agreement, and you understand that when your trial period ends, you will be required to provide billing information if you wish to continue using the service. Unlock the rest of this book Start a Free 10-Day Trial loading Learn about Safari for Business Have an account? Sign in.