JavaScript Intro • Certainly the most popular Web client-side programming technology today • Difficult to characterize – Many names • JavaScript, Jscript, ECMAScript, DHTML, etc. – Object Models Vary • Traditional DOM, IE4/5 Object Model, Nav 4, DOM Standard – Not studied rigorously like most programming langs • Lots of “copy-paste” scripters• Generated code from editors like Dreamweaver

JavaScript’s Origins – Netscape 3 (late 1995) • Originally called LiveScript – Goal: Form validation and basic user handling • Renamed JavaScript due to Java craze – Common misunderstanding about its relationship with Java– Not Java Lite, not as formal in OOP, etc. – Microsoft introduces Jscript in IE 3 • Clone of JavaScript and few incompatibilities – DHTML Wars of 4.x generation browsers • Both browsers introduce widely incompatible object models (e.g. Netscape 4 layers and IE’s document.all)