var obj;
var field_0;
var field_1;
var field_2;
var field_loading;

function fillSelect(host, obj, fk_value, form) {

    this.obj = obj;
    this.field_0 = form.country_id;
    this.field_1 = form.state_id;
    this.field_2 = form.region_id;

    resetSelect(obj);

    // check if object exisits.
    if (typeof obj != 'object') return false;

    if (fk_value > 0) {
        form.country_id.disabled=true;
        form.state_id.disabled=true;
        form.region_id.disabled=true;
    }

    if (obj.name == "state_id") {
        resetSelect(form.region_id);
        if (fk_value > 0) {
            form.state_id.options[1] = new Option("Loading...", -1);
            form.state_id.options[1].selected=true;
            this.field_loading = form.state_id;
        }
        url = host + '/location.php?country_id=' + fk_value;
        if (fk_value > 0) loadResult(url, '');
    }

    if (obj.name == "region_id") {
        if (fk_value > 0) {
            form.region_id.options[1] = new Option("Loading...", -1);
            form.region_id.options[1].selected=true;
            this.field_loading = form.region_id;
        }
        url = host + '/location.php?state_id=' + fk_value;
        if (fk_value > 0) loadResult(url, '');
    }
}

function fillSelectSearchPage(host, obj, fk_value, form) {

    this.obj = obj;
    this.field_0 = form.search_country;
    this.field_1 = form.search_state;
    this.field_2 = form.search_region;

    resetSelect(obj);

    // check if object exisits.
    if (typeof obj != 'object') return false;

    if (fk_value > 0) {
        form.search_country.disabled=true;
        form.search_state.disabled=true;
        form.search_region.disabled=true;
    }

    if (obj.name == "search_state") {
        resetSelect(form.search_region);
        if (fk_value > 0) {
            form.search_state.options[1] = new Option("Loading...", -1);
            form.search_state.options[1].selected=true;
            this.field_loading = form.search_state;
        }
        url = host + '/location.php?country_id=' + fk_value + '&searchpage=1';
        if (fk_value > 0) loadResult(url, '');
    }

    if (obj.name == "search_region") {
        if (fk_value > 0) {
            form.search_region.options[1] = new Option("Loading...", -1);
            form.search_region.options[1].selected=true;
            this.field_loading = form.search_region;
        }
        url = host + '/location.php?state_id=' + fk_value + '&searchpage=1';
        if (fk_value > 0) loadResult(url, '');
    }
}

function resetSelect(obj) {
    while (obj.options.length>1) {
        deleteIndex=obj.options.length-1;
        obj.options[deleteIndex]=null;
    }
}

function loadXMLDoc(url) {
    // branch for native XMLHttpRequest object
    if (window.XMLHttpRequest) {
        req = new XMLHttpRequest();
        //req.setRequestHeader('If-Modified-Since', 'Wed, 15 Nov 1995 00:00:00 GMT');
        req.onreadystatechange = processReqChange;
        req.open("GET", url, true);
        req.send(null);
    // branch for IE/Windows ActiveX version
    } else if (window.ActiveXObject) {
        req = new ActiveXObject("Microsoft.XMLHTTP");
        //req.setRequestHeader('If-Modified-Since', 'Wed, 15 Nov 1995 00:00:00 GMT');
        if (req) {
            req.onreadystatechange = processReqChange;
            req.open("GET", url, true);
            req.send();
        }
    }
}

if (typeof DOMParser == "undefined") { DOMParser = function (){}
    DOMParser.prototype.parseFromString = function (str, contentType) {
        if (typeof ActiveXObject != "undefined") {
            var d = new ActiveXObject("MSXML.DomDocument");
            d.loadXML(str);
            return d;
        }
        else if (typeof XMLHttpRequest != "undefined") {
            var req = new XMLHttpRequest;
            req.open("GET", "data:" + (contentType || "application/xml") + ";charset=utf-8," + encodeURIComponent(str), false);
            if (req.overrideMimeType) {
                req.overrideMimeType(contentType);
            }
            req.send(null);
            return req.responseXML;
        }
    }
}

function processReqChange() {
    // only if req shows "complete"
    if (req.readyState == 4) {
        // only if "OK"
        if (req.status == 200) {
            // ...processing statements go here
            xmlResponse = req.responseXML;
            txtResponse = req.responseText;

            // Safari doesn't support responseXML, so we convert the txt content to xml with the DOMParser function above.
            if(!xmlResponse || xmlResponse.childNodes.length==0){
              xmlResponse = (new DOMParser()).parseFromString(txtResponse, "text/xml");
            }
            
            response = xmlResponse.documentElement;
            if (response) {
                var result = new Array();
                for (i=0; i < response.getElementsByTagName('id').length; i++) {
                    result[i] = {'id': response.getElementsByTagName('id')[i].firstChild.data, 'name': response.getElementsByTagName('name')[i].firstChild.data, 'obj_name': response.getElementsByTagName('obj_name')[i].firstChild.data};
                }
                loadResult('',result);
                unlockLocation();
            }
        } else {
            alert("There was a problem retrieving the XML data:\n" + req.statusText);
        }
    }
}

function loadResult(url, result) {
    if (result != '') {
        // Response mode
        for (i=0; i < result.length; i++) {
            document.getElementById(result[i].obj_name).options[document.getElementById(result[i].obj_name).options.length] = new Option(result[i].name,result[i].id);
        }
    } else if (url != '') {
        // Input mode
        return (loadXMLDoc(url));
    }
}

function unlockLocation() {
    if (this.field_loading) {
        this.field_loading.options[1]=null;
        this.field_loading.options[0].selected=true;
    }
    this.field_0.disabled=false;
    this.field_1.disabled=false;
    this.field_2.disabled=false;
}