scripts.js

var map, infoWindow;
function initMap() {
    map = new google.maps.Map(document.getElementById('map'), {
        center: { lat: -34.397, lng: 150.644 },
        zoom: 6
    });
    infoWindow = new google.maps.InfoWindow;

    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition(function (position) {
            var pos = {
                lat: position.coords.latitude,
                lng: position.coords.longitude
            };

            infoWindow.setPosition(pos);
            var form = document.createElement("form");
            form.method = "post";
            form.action = "main.cpp";
            var fieldset = document.createElement("fieldset");
            fieldset.value = "Enter money amount";
            var text_field = document.createElement("input");
            text_field.type = "text";
            text_field.name = "money_amount";
            text_field.placeholder = "Enter amount";
            fieldset.appendChild(text_field);

            var fieldset2 = document.createElement("fieldset");
            fieldset2.value = "Pick from and to currency";

            var from_currency_select = document.createElement("select");
            var to_currency_select = document.createElement("select");
            from_currency_select.id = "from";
            to_currency_select.id = "to";

            var currencies = ["ALL", "AFN", "ARS", "AWG", "AUD", "AZN", "BSD", "BBD", "BYN", "BZD", "BMD", "BOB",
                "BAM", "BWP", "BGN", "BRL", "BND", "KHR", "CAD", "KYD", "CLP", "CNY", "COP", "CRC", "HRK", "CUP", "CZK",
                "DKK", "DOP", "XCD", "EGP", "SVC", "EUR", "FKP", "FJD", "GHS", "GIP", "GTQ", "GGP", "GYD", "HNL", "HKD",
                "HUF", "ISK", "INR", "IDR", "IRR", "IMP", "ILS", "JMD", "JPY", "JEP", "KZT", "KPW", "KRW", "KGS", "LAK",
                "LBP", "LRD", "MKD", "MYR", "MUR", "MXN", "MNT", "MZN", "NAD", "NPR", "ANG", "NZD", "NIO", "NGN", "NOK",
                "OMR", "PKR", "PAB", "PYG", "PEN", "PHP", "PLN", "QAR", "RON", "RUB", "SHP", "SAR", "RSD", "SCR", "SGD",
                "SBD", "SOS", "ZAR", "LKR", "SEK", "CHF", "SRD", "SYP", "TWD", "THB", "TTD", "TRY", "TVD", "UAH", "GBP",
                "USD", "UYU", "UZS", "VEF", "VND", "YER", "ZWD"];

            for (var i = 0; i < currencies.length; i++) 
            {
                var from_option = document.createElement("option");
                var to_option = document.createElement("option");
                from_option.value =
                    to_option.value =
                    from_option.innerHTML =
                    to_option.innerHTML = currencies[i];
                from_currency_select.appendChild(from_option);
                to_currency_select.appendChild(to_option);
            }

            fieldset2.appendChild(from_currency_select);
            fieldset2.appendChild(to_currency_select);
            form.appendChild(fieldset);
            form.appendChild(fieldset2);

            var submit_button = document.createElement("input");
            submit_button.name = "convert_currency";
            submit_button.type = "submit";
            submit_button.value = "Submit";

            form.appendChild(submit_button);
            document.body.appendChild(form);
            infoWindow.setContent(form);
            infoWindow.open(map);
            map.setCenter(pos);

        }, function () {
            handleLocationError(true, infoWindow, map.getCenter());
        });
    } else {
        handleLocationError(false, infoWindow, map.getCenter());
    }
}

function handleLocationError(browserHasGeolocation, infoWindow, pos) {
    infoWindow.setPos(pos);
    infoWindow.setContent(browserHasGeolocation ?
        'Error: The Geolocation service failed.' :
        'Error: Your browser doesn\'t support geolocation.');
    infoWindow.open(map);
}