Why is Javascript object not updating fields?
var imageType = "BoxArt";
var uploadReason = "New season";
var fileKey = "b2fc";

alert("imageType = " + imageType);
alert("uploadReason = " + uploadReason);
alert("fileKey = " + fileKey);

var iVO = { "images":{}};
var thisImage = fileKey;
iVO["images"][thisImage.fileKey] = thisImage;
iVO["images"][thisImage.imageType] = imageType;
iVO["images"][thisImage.uploadReason] = uploadReason;

alert("iVO['images'][thisImage.imageType] = " + iVO["images"][thisImage.imageType]);
alert("iVO['images'][thisImage.uploadReason] = " + iVO["images"]    [thisImage.uploadReason]);
alert("iVO['images'][thisImage.fileKey] = " + iVO["images"][thisImage.fileKey]);
alert("JSON.stringify(iVO):n" + JSON.stringify(iVO));

imageType = "BoxArt"
uploadReason = "New season"
fileKey = "b2fc"
iVO['images'][thisImage.imageType] = "New season"
iVO['images'][thisImage.uploadReason] = "New season"
iVO['images'][thisImage.fileKey] = "New season"
JSON.stringify(iVO):
{"images"}:{"undefined":"New season"}}

{
    "images":
    {
        "b2fc":
        {
            "imageType":"BoxArt",
            "uploadReason":"New season",
            "fileKey":"b2fc"
        }
    }
}

iVO["images"][thisImage.fileKey] = thisImage;
iVO["images"][thisImage.imageType] = imageType;
iVO["images"][thisImage.uploadReason] = uploadReason;

iVO['images'][thisImage] = {
         "imageType":"BoxArt",
        "uploadReason":"New season",
        "fileKey":"b2fc"
    };

iVO.images[thisImage] = {
         "imageType":"BoxArt",
        "uploadReason":"New season",
        "fileKey":"b2fc"
    };