Reading JSON sub-arrays dynamically

I am using JSON to dynamically populate a parent/child dropdown lists. I have it working to fill the parent drop down and have the child drop down filling with the same parent data. How do I loop through the sub array of the selected value from the parent?

My "each" line (key is the value from my parent DDL:

var key = $(this).prev("input").val();
$.each(jsondata.Id[key].HourTypeCodes, function(i, item) {

My JSON

[{
    "Id": 1,
    "Title": "Vacation",
    "HourTypeCodes": [
开发者_如何学Go        {
            "Id": "05",
            "Title": "VAC POLICE/FIRE" 
        },
        {
            "Id": "04",
            "Title": "VACATION" 
        },
        {
            "Id": "62",
            "Title": "VACATION HOURS PURCHASED" 
        },
        {
            "Id": "60",
            "Title": "VACATION SELL BACK" 
        } 
    ] 
},
{
    "Id": 2,
    "Title": "Holiday",
    "HourTypeCodes": [
        {
            "Id": "08",
            "Title": "HOLIDAY" 
        } 
    ] 
},
{
    "Id": 3,
    "Title": "Floating Holiday",
    "HourTypeCodes": [
        {
            "Id": "09",
            "Title": "FLOATING HOLIDAY" 
        } 
    ] 
}]

I figured it out finally! I found this: http://inderpreetsingh.com/2010/10/14/javascriptjson-find-index-in-an-array-of-objects/

From there these are the two lines that work:

    var i = findIndexByKeyValue(jsonRequestType, "Id", key);
    $.each(jsonRequestType[i].HourTypeCodes, function(i, item) {