Google Maps API

Hi Guys!

I need to build a system that does the following using the Google Maps API:

  1. You enter a postcode or town (onkeyup the location of the postcode/town will be plotted on the map and marked by a pin)
  2. You enter a radius (onkey up this will draw a radius circle on the map)
  3. You enter a second radius (onkey up this will draw another radius circle on the map in a different color)

Has anyone done anything like this before?

Thanks in advance.