Google Maps V3 javascript -- customizing the infowindow when clicking pins -

hey guys -- looking create entire custom info window pin description. not looking insert custom div within popup window, redesign window itself.

i saw article on here http://koti.mbnet.fi/ojalesa/boundsbox/tiptool_trains.htm not i'm looking for, rounded bubble needs go

i hoping find article or tips on how go this? right i'm thinking of creating custom overlay extendin functionality of extendable classes/functions of api. place start be? has done here?

thanks guys!

there custom infowindow example in demo gallery section of google map api documentation.