function pier_document_widget_update(id) {
	var source = document.getElementById(id);
	var target = document.getElementById(id + "_copy");
	target.value = source.value;
}
function pier_document_widget_register(id) {
	var source = document.getElementById(id);
	var target = document.createElement("input");
	target.setAttribute("name", source.name);
	target.setAttribute("id", id + "_copy");
	target.setAttribute("type", "hidden");
	document.forms[0].appendChild(target);
	pier_document_widget_update(id);
}