How can i get the driving directions between two points in my city with Google Maps API?

I have a problem, I don't know how to give driving directions between to random points inside a map of my city. If I use GDirections() object of Google Maps API, it shows only directions of a few known streets and objects in my city, and not for all :( Can someone help me please to figure it out.

Thanks anyway!How can i get the driving directions between two points in my city with Google Maps API?
I like Yahoo Maps.How can i get the driving directions between two points in my city with Google Maps API?
Why not use Mapquest?



http://www.mapquest.com/