Passing %this from gui objects

I've been trying to write gui functions that will work for a family of buttons, rather than writing one function per button. The example here is a function that will let a button change its own text value. My assumption was that I'd just reference %this in the function called, and everything would be happy, but this doesn't seem to work.

Witness:

..... assorted gui stuff....
new GuiButtonCtrl(MajorAName) {
...
command = "MajorAName.renameButton();";
....
};
new GuiButtonCtrl(Lieutenant1AName) {
....
command = "renameButton();";
....
};


function renameButton(%this)
{
echo(%this.text);
%this.foo();
}

function MajorAName::renameButton(%this)
{
echo(%this.text);
%this.foo();
}

function MajorAName::foo(%this)
{
echo("I am the very model of a modern major general.");
}

So the first button calls an explicitly defined version of the function just for that one gui object, and its %this reference works. Meanwhile, the generic version of the function called by the second button doesn't work. I've tried a number of variations on this scheme without success. Anybody clue me in?

(I'm aware of the bug in this current version of the test that Lieutenant1A name won't be able to call a foo function that doesn't exist, but back when MajorA was attempting to call the same function from the generic renameButton, it didn't work, either. You're seeing test code variation in progress here.)

S.