Google map with highlighted locations

I want google map with highlighted locations using html or classic asp. How can i do it? Please check the link.

This is sample link.

They've created separate overlays, in which they're layering transparent PNG images over the top of a map,

e.g. http://www.shelbybb.com/gunnel.png

And the code to add it to the map:

var gunnelBounds = new google.maps.LatLngBounds(new google.maps.LatLng(38.01051, -85.00043), new google.maps.LatLng(38.54504, -83.97889));
        var gunnelmap = new google.maps.GroundOverlay("gunnel.png", gunnelBounds);
        gunnelmap.setMap(map);