"prototype" actionscript keyword

Hi All,

I'm desperately trying to develop a map viewer with ming CVS 3a, 
now I have problems compiling short actionscript code like that below.

Does anybody know if ming 3.a actioncompiler supports the keyword 
"prototype"??


[...]
$movie->add( new SWFAction("
Dog = function( age )
{
  this.age = age;
}


Dog.prototype.haveBirthday = function( )
{
  this.age++;
}

yeller = new Dog( 12 );
info_text = yeller.age; 
yeller.haveBirthday( );  

[...]


there is a parse error on the line where prototype is.

(I had the same problem in other pieces of code where prototype was)


TIA


-- 
Alessandro Pasotti