window.onload = init;

function init() {

	var estado = $('estado');
	
	estado.onchange = function() {

		var url = 'include/backend_cidades.php';
		var pars = "uf=" + $F('estado') + "&diff=" + new Date().getTime();
		
		writeLoading('loading_estado');

		var myAjax = new Ajax.Request(
			url, {asynchronous: true, method: 'get', evalScripts: true, parameters: pars, onFailure: reportError, onComplete: showResponseCities }
		);
		
		return false;
	}
	
	return true;
}

function writeLoading(divRef) {
	$(divRef).className = "loadingMessage";
	$(divRef).innerHTML = "Enviando";
	$('cidade').disabled = true;
}

function showResponseCities(request) {
	$('loading_estado').innerHTML = "";
	var xmlDoc = request.responseXML;
	var cities = xmlDoc.getElementsByTagName("city");
	var opt = "";
	var opt_txt = "";
	$('cidade').innerHTML = "";	
	for(i=0;i<cities.length;i++) {
		opt = document.createElement("option");
		opt_txt = document.createTextNode(cities[i].firstChild.nodeValue);
		opt.appendChild(opt_txt);
		opt.setAttribute("value", cities[i].firstChild.nodeValue);
		$('cidade').appendChild(opt);
	}
	$('cidade').disabled = false;
}

function reportError(request) {
	alert('Sorry. There was an error.');
}