diafol
Rhod Gilbert Fan (ardav)
7,792 posts since Oct 2006
Reputation Points: 1,170
Solved Threads: 1,080
The geolocation ensures that the user will be placed on the googlemap without any need to enter anything. Without the 'address' from the postal code, how could an image map decide where to place you? I'd say, your best bet would be to cut up the country/region in your GoogleMap into polygons (based on lat/long coords), using a coloured translucent overlay (max 4 or 5 colours as used in atlases), you should be able to sort this out without much hassle.
If auto-geolocation doesn't work, just have a textbox for postal code which should then centre the map around this marker (polygons intact!).
It should be noted that postal codes do not describe areas that will fall in line with your polygons (well, I assume not), so there will be a margin of uncertaintly at the borders of your zones.
Image maps are great for what they are - for static images. They aren't brilliant for interactive maps - more like a headache! Trying to keep track of all that coordinate data - no, not nice.
diafol
Rhod Gilbert Fan (ardav)
7,792 posts since Oct 2006
Reputation Points: 1,170
Solved Threads: 1,080