var dictionary = new ActiveXObject("Scripting.Dictionary");

dictionary.Add(キー,値);

dictionary.Item(キー);

var arr = (new VBArray(dictionary.Keys())).toArray();

<script type="text/javascript">
<!--
function a(){
    var dictionary = new ActiveXObject("Scripting.Dictionary");
    dictionary.Add("test1","100");
    dictionary.Add("test2","200");

    var arr = (new VBArray(dictionary.Keys())).toArray();
    for(i in arr){
        alert(arr[i]);
    }
}
//-->
</script>

dictionary.Add("1","100");
dictionary.Add(1,"200");

<input type="button" value="ボタン" onclick="b();" />
<script type="text/javascript">
<!--
function b(){
    var dictionary = new ActiveXObject("Scripting.Dictionary");
    dictionary.Add("1","100");
    dictionary.Add(1,"200");

    var arr = (new VBArray(dictionary.Items())).toArray();
    for(i in arr){
        alert(arr[i]);
    }
}
//-->
</script>

<script type="text/javascript">
<!--
function c(){
    var dictionary = new ActiveXObject("Scripting.Dictionary");
    dictionary.Add("1","100");
    dictionary.Add(1,"200");

    dictionary.Remove(1);
    if(dictionary.Exists("1")){
        alert("キー=\"1\"は存在します");
    }
    if(!dictionary.Exists(1)){
        alert("キー=1は存在しません");
    }

    // キーを変更
    dictionary.Key("1") = "2";
    // 値を変更
    dictionary.Item("2") = "test変更";

    var arr = (new VBArray(dictionary.Items())).toArray();
    for(i in arr){
        alert(arr[i]);
    }

    var arr = (new VBArray(dictionary.Keys())).toArray();
    for(i in arr){
        alert(arr[i]);
    }
}
//-->
</script>