TileOverlay

###Add a TileOverlay A tile overlay is an image that is fixed to a map. To add an image, call addTileOverlay() method. The map.addTileOverlay() method takes a single overlay options object literal, specifying the initial properties of the tile overlay.

The following fields are available when constructing a ground overlay:

Field Name	Type	Description
url	String	The url of the tile image. You must include <x>,<y> and <zoom> strings into your URL.
visible	Boolean	false if you want to hide the ground overlay.
zIndex	Number	Specify the zIndex.

map.addTileOverlay({
  // <x>,<y> and <zoom> are replaced with values
  tileUrlFormat: "http://tile.stamen.com/watercolor/<zoom>/<x>/<y>.jpg"
}, function(tileOverlay) {
  mTileOverlay = tileOverlay;
  map.showDialog();
});