fileuplaod_wgt.buttonBar.find("button.cancel")
fileuplaod_wgt.buttonBar.find("button.start")
fileuplaod_wgt.buttonBar.find('input[type=file]')
upload content
upload.uploadContent'
number of uploaded files
var files = fileuplaod_wgt.uploadContent.find('.files .template-upload');
invalid files
fileuplaod_wgt.uploadContent.find("tr.ui-state-error");
reference:
http://stackoverflow.com/questions/14881131/primefaces-upload-how-to-only-allow-one-upload-in-advance-mode
