1) You can set the objects doorway_mode via the constructor or the property...
   var g = new Graphic(undefined,undefined,undefined,undefined, true );
   g.doorway_mode = false;
   If you do this, it will always be whatever you set it to.

2) You can use "the default" by not specifying the mode...
   var g = new Graphic();

3) You can change what "the default" is by modifying the prototype:
   g.prototype.doorway_mode = true;

When you do #3, *all* instances of the class that use "the default" will
use the new value.  So if you have a bunch of Graphic objects, and switch
to doorway mode, you can now change them all to output in doorway mode
with a single assignment.

Whee!