Google Maps Geocode Undefined

I have this code which is initated on load

// Display the map

function map_it() {
    var myLatlng = new google.maps.LatLng(13.005621, 77.577531);
    var myOptions = {
        zoom: zoomLevel,
        center: myLatlng,
        disableDefaultUI: true,
        mapTypeId: google.maps.MapTypeId.ROADMAP,
        navigationControl: true,
        navigationControlOptions: {
            style: google.maps.NavigationControlStyle.SMALL
        }
    }
    map = new google.maps.Map(document.getElementById("map-it"), myOptions);
    var marker = new google.maps.Marker({
        position: myLatlng,
        map: map,
        draggable: true
    });
    google.maps.event.addListener(marker, 'dragend', function (event) {
        document.getElementById('mapLat').value = marker.getPosition().lat();
        document.getElementById('mapLng').value = marker.getPosition().lng();
        geocodePosition(marker.getPosition());
    });
}

function geocodePosition(pos) {
    geocoder.geocode({
        latLng: pos
    }, function (responses) {
        if (responses && responses.length > 0) {
            updateMarkerAddress(responses[0].formatted_address);
            alert(responses[0].formatted_address);
        } else {
            updateMarkerAddress('Cannot determine address at this location.');
        }
    });
}

i get the following error

geocoder is not defined
http://localhost/bakasura1/js/modal.js
Line 74