How the blue dot in google maps is centered at the current location?

i have several questions about the blue dot that appears when i launch t开发者_开发百科he google maps in the browser. I tried implementing the same by using the blue dot image as the icon property of the marker and changing the position of the marker in accordance with the current location. So when i do this its actually like the maps are refreshing where as in the google maps application the blue dot is moving smoothly(and that's very awesome). My question is whether blue dot in google maps is implemented as a marker which changes its position or is it an inbuilt property of google maps which we can use.

i am using google maps API v3 to do this.

Thanks for any information.

It's a marker with custom icon which is placed with HTML 5 position provided by most recent browsers.

When the position change, you can change marker position.

http://www.kmcgraphics.com/google/