Possible Duplicate:
check if map markers are within selected bounds
I have couple hundreds markers, but for convenience, I would like to 'grey-out' some options for markers which are not currently visible on the map (they are on the map, but outside the currently viewed map boundaries.)
As a solution, I think that I need to loop over all my markers (I have an array, so this is not a problem), but I don't know how to check if marker is currently within visible boundaries.