window.onload = init;

function init() {

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

		var url = 'backend/subregions.php';
		var pars = "region_id=" + $F('region');
		
		writeLoading('subreg0');

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

function writeLoading(divRef) {
	$(divRef).innerHTML = "carregando subregiões...";
	$('subreg').disabled = true;
}

function showResponseSubregions(request) {
	var xmlDoc = request.responseXML;
	var subregions = xmlDoc.getElementsByTagName("subregion");
	var opt = "";
	var opt_txt = "";
	$('subreg').innerHTML = "";	
	opt = document.createElement("option");
	opt.appendChild(document.createTextNode("selecione uma subregião"));
	opt.setAttribute("id", "subreg0");
	opt.setAttribute("value", "0");
	$('subreg').appendChild(opt);


	for(i=0;i<subregions.length;i++) {
		opt = document.createElement("option");
		opt_txt = document.createTextNode(subregions[i].getElementsByTagName("name")[0].firstChild.nodeValue);
		opt.appendChild(opt_txt);
		opt.setAttribute("value", subregions[i].getElementsByTagName("id")[0].firstChild.nodeValue);
		$('subreg').appendChild(opt);
	}
	$('subreg').disabled = false;
}

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