Can't initiate the google.maps.Geocoder

I don't understand why but i'm getting this error when I try to initialize the google.maps.Geocoder.

Here is the error:

Uncaught TypeError: undefined is not a function

And the code :

function updateMapPosition(map){
    var geocoder = new google.maps.Geocoder(); //crashes here !!
    var position = geocoder.geocode( {'address':$('#id_address').val()},
        function(results,status){
            if(status == google.maps.GeocoderStatus.OK){
                if (status != google.maps.GeocoderStatus.ZERO_RESULTS) {
                    map.setCenter(results[0].geometry.location);
                    var marker = new google.maps.Marker({map:map, position:results[0].geometry.location});
                }
                else{
                    alert("hop")
                }
            }
        }
    )
}