function addFileInputEvent(namespace, field) {
    AUI().use('aui-base', function (A) {
        A.one("#" + namespace + field).on('change', function () {
            var input = A.one("#" + namespace + field);
            var fileList = input.getDOM().files;
            var numFiles = fileList ? fileList.length : 1;
            var label = input.val().replace(/\\/g, '/').replace(/.*\//, '');
            var info = A.one("#" + namespace + field + '_INFO');
            if (numFiles > 1) {
                info.setHTML(numFiles + " files");
            } else {
                info.setHTML(label);
            }
        });
    })
}