Mozilla has very complete docs:
https://developer.mozilla.org/en/JavaScript/Reference
DevGuru has a very complete list also
http://www.devguru.com/technologies/ecmascript/quickref/javascript_index.html
in addition if you want to see all the quirky differences that Microsoft implemented then MSDN provides a fairly complete (but not frequently updated or corrected) set of docs here:
http://msdn.microsoft.com/en-us/library/ms533054%28v=VS.85%29.aspx