Google maps JavaScript v3 undefined error

I am trying to add a marker to a map in Google maps using JavaScript. The console on from Google Chrome is returning "Uncaught TypeError: undefined is not a function". The error appears right after the map = new google.maps.Map. However if I take out the Marker code the map appears and there are no errors.

The code I am using is

<script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCs7h9k3_PHQpo8EBDf-GaVhf178Z3xSb4&sensor=false"></script>
<script type="text/javascript">
var map;
function initialize() {
   var mapOptions = {
   zoom: 8,
   center: new google.maps.LatLng(35.6017, -77.3725)
};

map = new google.maps.Map(document.getElementById('gmap'),
mapOptions);

var marker = new google.maps.Marker({
    position: new google.maps.Latlng(36, -77),
    map: map,
    title: 'Test' 
});

}
google.maps.event.addDomListener(window, 'load', initialize);
</script>