/me думает: гм...
<html>
<head>
<title>Main Form</title>
<script type="text/javascript">
<!--
var
a1,
a2,
a3;
function foo()
{
alert("arr instanceof Array="+(arr instanceof Array));
alert("arr.length="+arr.length);
for(var i=0; i<arr.length; ++i)
{
alert("arr["+i+"]="+arr[i]);
a1=arr[i];
alert(a1);
}
}
// -->
</script>
</head>
<body>
<iframe id="IFrame1" src="iframe1.html"></iframe>
</body>
</html>
<html>
<head>
<title>IFrame1</title>
<script type="text/javascript">
<!--
function CreateArray()
{
window.parent.arr=new window.parent.Array(1,2,3);
window.parent.foo();
}
// -->
</script>
</head>
<body>
<input type="button" id="Button3" value="CreateArray()" onclick="CreateArray()">
</body>
</html>
Все - сухо... (Mozilla Firefox 3.5.7, M$ IE 6.0.2900.2180.xpsp_sp2_rtm040803-2158) Даже
instanceof Array