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.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");
                if (req) {
                        req.onreadystatechange = processReqChange;
                        req.open("GET", url, true);
                        req.send();
                }
        }
}

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