How does the certain version of a certain brower support the JavaScript Standard?(come from Javascri

Table 1-2. Client-side JavaScript features by browser

Browser	Language	DOM capabilities
Netscape 2	JavaScript 1.0	Form manipulation
Netscape 3	JavaScript 1.1	Image rollovers
Netscape 4	JavaScript 1.2	DHTML with Layers
Netscape 4.5	JavaScript 1.3	DHTML with Layers
Netscape 6 / Mozilla	JavaScript 1.5	Substantial support for W3C DOM standard; support for Layers discontinued
IE 3	JScript 1.0/2.0	Form manipulation
IE 4	JScript 3.0	Image rollovers; DHTML with document.all[]
IE 5	JScript 5.0	DHTML with document.all[]
IE 5.5	JScript 5.5	Partial support for W3C DOM standard
IE 6	JScript 5.5	Partial support for W3C DOM standard; lacks support for W3C DOM event model

Table 1-1. Versions of JavaScript

Version	Description
JavaScript 1.0	The original version of the language. It was buggy and is now essentially obsolete. Implemented by Netscape 2.
JavaScript 1.1	Introduced a true Array object; most serious bugs resolved. Implemented by Netscape 3.
JavaScript 1.2	Introduced the switch statement, regular expressions, and a number of other features. Almost compliant with ECMA v1, but has some incompatibilities. Implemented by Netscape 4.
JavaScript 1.3	Fixed incompatibilities of JavaScript 1.2. Compliant with ECMA v1. Implemented by Netscape 4.5.
JavaScript 1.4	Implemented only in Netscape server products.
JavaScript 1.5	Introduced exception handling. Compliant with ECMA v3. Implemented by Mozilla and Netscape 6.
JScript 1.0	Roughly equivalent to JavaScript 1.0. Implemented by early releases of IE 3.
JScript 2.0	Roughly equivalent to JavaScript 1.1. Implemented by later releases of IE 3.
JScript 3.0	Roughly equivalent to JavaScript 1.3. Compliant with ECMA v1. Implemented by IE 4.
JScript 4.0	Not implemented by any web browser.
JScript 5.0	Supported exception handling. Partially compliant with ECMA v3. Implemented by IE 5.
JScript 5.5	Roughly equivalent to JavaScript 1.5. Fully compliant with ECMA v3. Implemented by IE 5.5 and IE 6. (IE 6 actually implements JScript 5.6, but 5.6 is not different from 5.5 in any way that is relevant to client-side JavaScript programmers.)
ECMA v1	The first standard version of the language. Standardized the basic features of JavaScript 1.1 and added a few new features. Did not standardize the switch statement or regular expression support. Conformant implementations are JavaScript 1.3 and JScript 3.0.
ECMA v2	A maintenance release of the standard that included clarifications but defined no new features.
ECMA v3	Standardized the switch statement, regular expressions, and exception handling. Conformant implementations are JavaScript 1.5 and JScript 5.5.