var http = createRequestObject();
var http2 = createRequestObject();

function createRequestObject() {
    var ro;
    var browser = navigator.appName;
    if(browser == "Microsoft Internet Explorer"){
        ro = new ActiveXObject("Microsoft.XMLHTTP");
    }else{
        ro = new XMLHttpRequest();
    }
    return ro;
}

function loading(){
    var id = document.getElementById('l1').value;
     
    if (id == "21") {
   
    	document.getElementById('estero').style.display = "block";

    	
    } else {
    
	    http.open('GET','get.php?id='+id, true);
	    http.onreadystatechange = getState;
	    http.send(null);
    }
}

function loading2(){
    var id = document.getElementById('l2').value;

    http2.open('GET','get2.php?id='+id, true);
    http2.onreadystatechange = getState2;
    http2.send(null);
}

function getState(){
    var newOption;
    var where = (navigator.appName == "Microsoft Internet Explorer") ? -1 : null;
    var State = document.getElementById('l2');
    while (State.options.length) {
        State.remove(0);
    }
    id = document.getElementById('l1').value;

    if(id == 'sel'){
        document.getElementById('l2').disabled = true;
        newOption = document.createElement("option");
        newOption.value = 'sel';
        newOption.text = 'Seleziona una Provincia:';
        State.add(newOption, where);
    }else{
        if(http.readyState == 4){
            if (http.status == 200) {
                var response = http.responseText;
                    if(response == ''){
                        document.getElementById('l2').disabled = true;
                        newOption = document.createElement("option");
                        newOption.value = 'sel';
                        newOption.text = 'Nessuna voce';
                        State.add(newOption, where);
                    }else{
                        
                        coppia = response.split(',');
                        max = coppia.length;
                        newOption = document.createElement("option");
                        newOption.value = 'sel';
                        newOption.text = '-';
                        State.add(newOption, where);
                            for(x=0;x<max;x++){
                                val = coppia[x].split('-');
                                newOption = document.createElement("option");
                                newOption.value = val[0];
                                newOption.text = val[1];
                                State.add(newOption, where);
                            }
                            document.getElementById('l2').disabled = false;
                        }
                    }
                }
    }
}

function getState2(){
    var newOption;
    var where = (navigator.appName == "Microsoft Internet Explorer") ? -1 : null;
    var State = document.getElementById('l3');
    while (State.options.length) {
        State.remove(0);
    }
    id = document.getElementById('l2').value;

    if(id == 'sel'){
        document.getElementById('l3').disabled = true;
        newOption = document.createElement("option");
        newOption.value = 'sel';
        newOption.text = 'Seleziona un Comune:';
        State.add(newOption, where);
    }else{
        if(http2.readyState == 4){
            if (http2.status == 200) {
                var response = http2.responseText;
                    if(response == ''){
                        document.getElementById('l3').disabled = true;
                        newOption = document.createElement("option");
                        newOption.value = 'sel';
                        newOption.text = 'Nessuna voce';
                        State.add(newOption, where);
                    }else{
                        coppia = response.split(',');
                        max = coppia.length;
                        newOption = document.createElement("option");
                        newOption.value = 'sel';
                        newOption.text = '-';
                        State.add(newOption, where);
                            for(x=0;x<max;x++){
                                val = coppia[x].split('-');
                                newOption = document.createElement("option");
                                newOption.value = val[0];
                                newOption.text = val[1];
                                State.add(newOption, where);
                            }
                            document.getElementById('l3').disabled = false;
                        }
                    }
                }
    }
}