How to store multiple related values in javascript?

This is something I did before:

<input type="checkbox" id="sample">
<input data-requires="sample" data-default="Default">

function applyControls(){
    $("input[data-requires]").each(function(){
        var target = $(this);
        $("#" + target.data("requires")).click(function(){
            if(this.checked){
                target.prop("disabled", false);
            }else{
                target.prop("disabled", true).val(target.data("default"));
            }
        });
    });
}
applyControls();

^{Note: This code is written with jQuery. You can easily convert this to native code by substituting jQuery methods with native methods.}

Demo: http://jsfiddle.net/DerekL/VnHAc/

Now this way you don't have to create any map or Object to store these relations (you don't even need ids for individual textboxes!) By using data-* attributes, you do not have to modify a "map" every single time you add connections. In fact, this is the preferred way¹ of doing it in HTML5.

_{¹ https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Using_data_attributes}