Функции JScript.

Способ более простой: Воспользоваться встроенными функциями, возвращающими номер версии JScript.

А вот код скрипта, внедренного в эту страницу:

<script language="JScript" type="text/javascript">
document.write("Ваш Интернет - браузер использует интерпретатор: ")
document.write(ScriptEngine( ))
document.write(" ")
document.write(ScriptEngineMajorVersion( ))
document.write(".")
document.write(ScriptEngineMinorVersion( ))
</script>

Host Application	JScript Version
	1.0	2.0	3.0	4.0	5.0
Microsoft Internet Explorer 3.0	x
Microsoft Internet Information Server 1.0		x
Microsoft Internet Explorer 4.0			x
Microsoft Internet Information Server 4.0			x
Microsoft Windows Scripting Host 1.0			x
Microsoft Visual Studio 6.0				x
Microsoft Internet Explorer 5.0					x
Microsoft Internet Information Services 5.0					x

Следующая таблица укажет Вам, в какой версии языка JScript функция была реализована впервые.

Language Element	Version First Introduced
	1.0	2.0	3.0	4.0	5.0
$1...$9 Properties			x
abs Method	x
acos Method	x
ActiveXObject Object			x
Addition Operator (+)	x
anchor Method	x
arguments Property		x
Array Object		x
asin Method	x
Assignment Operator (=)	x
atan Method	x
atan2 Method	x
atEnd Method			x
big Method	x
Bitwise AND Operator (&)	x
Bitwise Left Shift Operator (<<)	x
Bitwise NOT Operator (~)	x
Bitwise OR Operator (|)	x
Bitwise Right Shift Operator (>>)	x
Bitwise XOR Operator (^)	x
blink Method	x
bold Method	x
Boolean Object		x
break Statement	x
caller Property		x
catch Statement					x
@cc_on Statement			x
ceil Method	x
charAt Method	x
charCodeAt Method			x
Comma Operator (,)	x
// (Single-line Comment Statement)	x
/*..*/ (Multiline Comment Statement)	x
Comparison Operators	x
compile Method			x
concat Method (Array)			x
concat Method (String)			x
Conditional Compilation			x
Conditional Compilation Variables			x
Conditional (trinary) Operator (?:)	x
constructor Property		x
continue Statement	x
cos Method	x
Data Type Conversion			x
Date Object	x
Decrement Operator (--)	x
delete Operator			x
description Property					x
dimensions Method			x
Division Operator (/)	x
do...while Statement			x
E Property	x
Enumerator Object			x
Equality Operator (==)	x
Error Object					x
escape Method	x
eval Method	x
exec Method			x
exp Method	x
fixed Method	x
floor Method	x
fontcolor Method	x
fontsize Method	x
for Statement	x
for...in Statement					x
fromCharCode Method			x
Function Object		x
function Statement	x
getDate Method	x
getDay Method	x
getFullYear Method			x
getHours Method	x
getItem Method			x
getMilliseconds Method			x
getMinutes Method	x
getMonth Method	x
GetObject Function			x
getSeconds Method	x
getTime Method	x
getTimezoneOffset Method	x
getUTCDate Method			x
getUTCDay Method			x
getUTCFullYear Method			x
getUTCHours Method			x
getUTCMilliseconds Method			x
getUTCMinutes Method			x
getUTCMonth Method			x
getUTCSeconds Method			x
getVarDate Method			x
getYear Method	x
Global Object			x
Greater than Operator (>)	x
Greater than or equal to Operator (>=)	x
Identity Operator (===)	x
@if Statement			x
if...else Statement	x
Increment Operator (++)	x
index Property			x
indexOf Method	x
Inequality Operator (!=)	x
Infinity Property			x
input Property			x
instanceof Operator					x
isFinite Method			x
isNaN Method	x
italics Method	x
item Method			x
join Method		x
Labeled Statement			x
lastIndex Property			x
lastIndexOf Method	x
lbound Method			x
length Property (Array)		x
length Property (Function)		x
length Property (String)	x
Less than Operator (<)	x
Less than or equal to Operator (<=)	x
link Method	x
LN2 Property	x
LN10 Property	x
log Method	x
LOG2E Property	x
LOG10E Property	x
Logical AND Operator (&&)	x
Logical NOT Operator (!)	x
Logical OR Operator (||)	x
match Method			x
Math Object	x
max Method	x
MAX_VALUE Property		x
min Method	x
MIN_VALUE Property		x
Modulus Operator (%)	x
moveFirst Method			x
moveNext Method			x
Multiplication Operator (*)	x
NaN Property (Global)			x
NaN Property (Number)		x
NEGATIVE_INFINITY Property		x
new Operator	x
Nonidentity Operator (!==)	x
Number Object		x
number Property					x
Object Object			x
Operator Precedence	x
parse Method	x
parseFloat Method	x
parseInt Method	x
PI Property	x
POSITIVE_INFINITY Property		x
pow Method	x
prototype Property		x
random Method	x
RegExp Object			x
Regular Expression Object			x
Regular Expression Syntax			x
replace Method	x
return Statement	x
reverse Method		x
round Method	x
ScriptEngine Function		x
ScriptEngineBuildVersion Function		x
ScriptEngineMajorVersion Function		x
ScriptEngineMinorVersion Function		x
search Method			x
@set Statement			x
setDate Method	x
setFullYear Method			x
setHours Method	x
setMilliseconds Method			x
setMinutes Method	x
setMonth Method	x
setSeconds Method	x
setTime Method	x
setUTCDate Method			x
setUTCFullYear Method			x
setUTCHours Method			x
setUTCMilliseconds Method			x
setUTCMinutes Method			x
setUTCMonth Method			x
setUTCSeconds Method			x
setYear Method	x
sin Method	x
slice Method (Array)			x
slice Method (String)			x
small Method	x
sort Method		x
source Property			x
split Method			x
sqrt Method	x
SQRT1_2 Property	x
SQRT2 Property	x
strike Method	x
String Object	x
sub Method	x
substr Method			x
substring Method	x
Subtraction Operator (-)	x
sup Method	x
switch Statement			x
tan Method	x
test Method			x
this Statement	x
throw Statement					x
toArray Method			x
toGMTString Method	x
toLocaleString Method	x
toLowerCase Method	x
toString Method		x
toUpperCase Method	x
toUTCString Method			x
try Statement					x
typeof Operator	x
ubound Method			x
Unary Negation Operator (-)	x
unescape Method	x
Unsigned Right Shift Operator (>>>)	x
UTC Method	x
valueOf Method		x
var Statement	x
VBArray Object			x
void Operator		x
while Statement	x
with Statement	x