var request;

function start_preview(obj) {
    var phone_number = document.getElementById('phone_number').value;
    var user_name = document.getElementById('user_name').value;

    var preview_name_select_box = document.getElementById('preview_name_select_box');
    var preview_name = preview_name_select_box.options[preview_name_select_box.selectedIndex].value;

    if(phone_number == null || phone_number == '') {
        alert("A phone number is required.");
        return false;
    }
    if(user_name == null || user_name == '') {
        alert("A name is required.");
        return false;
    }

    document.getElementById('preview_button').disabled = true;
    document.getElementById('message').innerHTML = ' ';

    var url = "cgi-bin/group_call_preview.cgi";
    post_request(url, "phone_number=" + phone_number + "&preview_name=" + preview_name + "&user_name=" + user_name);
}

function post_request(url, params) {
    request = false;
    if (window.XMLHttpRequest) { // Mozilla, Safari,...
        request = new XMLHttpRequest();
        if (request.overrideMimeType) {
            // set type accordingly to anticipated content type
            //request.overrideMimeType('text/xml');
            request.overrideMimeType('text/x-json');
        }
    } else if (window.ActiveXObject) { // IE
        try {
            request = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try {
                request = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {}
        }
    }
    if (!request) {
        alert('Cannot create XMLHTTP instance');
        document.getElementById('preview_button').disabled = false;
        return false;
    }

    request.onreadystatechange = response_handler;
    request.open('POST', url, true);
    request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    request.setRequestHeader("Content-length", params.length);
    request.setRequestHeader("Connection", "close");
    request.send(params);
}

// This is called when we get a response to a post
function response_handler() {
    if (request.readyState == 4 || request.readyState == "complete") {
        document.getElementById('preview_button').disabled = false;

        if (request.status == 200) {
            var object = eval('(' + request.responseText + ')');
            document.getElementById('message').innerHTML = object.message;
            if(!object.success) {
                document.getElementById('message').style.color = "red";
            } else {
                document.getElementById('message').style.color = "blue";
            }
            return 1;
        } else {
            alert('There was a problem with the request.\n Status: ' + request.status);
        }
    }
}

function toggle_scenario_desc() {
    var preview_name_select_box = document.getElementById('preview_name_select_box');
    var preview_name = preview_name_select_box.options[preview_name_select_box.selectedIndex].value; 
    document.getElementById('scenario_desc_1').style.display = 'none';
    document.getElementById('scenario_desc_2').style.display = 'none';
    document.getElementById('scenario_desc_3').style.display = 'none';
    document.getElementById('scenario_desc_4').style.display = 'none';

    var scenario_num = 1;
	if(preview_name == "weather") {
        scenario_num = 2;
    } else if(preview_name == "business_cont") {
        scenario_num = 3;
    } else if(preview_name == "validation") {
        scenario_num = 4;
    }

    document.getElementById('scenario_desc_' + scenario_num).style.display = '';
}