In reply to Hans de Wit.

Hans, if you want to use custom markers, you need to add icon option to the marker definition, e.g.
'var marker' i '= new google.maps.Marker({' /
'position: point' i ',' /
'map: map,' /
'icon: ' brand ',' /
'title: "Click here for details"' /
'});' /
where variable brand holds URLs to your marker images. Does this work for you?