function Thing( a, b ) {

	this.c = a * b;

	function doubleC( c ) {
		document.writeln( 'function doubleC(), this.c is ' + c );
		return c * 2;
	}

	this.cDoubled = function () {
		document.writeln( 'this.cDoubled()' );
		return doubleC( this.c );
	}

	this.getThisC = function () {
		return this.c;
	}

}

var t = new Thing( 2, 3 );
document.writeln( t.cDoubled() );