Many a times, Java Script developers are perplexed by the fact that the same piece of Java Script code written by them behaves differently on the different web browsers. The reason for the same is the different implementations of the ECMA Script language which comes with various browsers. Here is a draft of JScript Deviations from ES3 which captures some of this.
So, now if you have a Java Script or JScript code which behaves differently on different browsers, take a look at this document. It might have the snwer to your problem.
Read more about this at Pratap’s blog ECMAScript3 and beyond.