JavaScript + Google Maps

hello all,

what i would like to implement is the following :
http://mon.grnet.gr/network/maps/lite/?load&ip

but, the problem is that, although the numerical data that show the traffic volume passing through a link are available to me,
i do not have clue on how i can display them onto the map … ?

i would be thankful, if you could give me a piece of advice.