[jQuery] Modifyng a plugin, how to pass and execute a callback function?

[Giovanni Battista Lenoci]

Hi, I'm trying to modify the pngfix plugin to be able to launch a
function after the pngfix has applied, anyone can help me?

I've writed a few lines of code:

function test() {
  alert('prot');
}

$(document).pngFix({'blankgif':'images/pngfix/blank.gif', 'funzione':
test});

and inside the plugin If I do an alert of "settings.funzione" I can
see the code of the function "test", but How can I launch It?

Sorry, I'm not very expert on javascript, and I'm looking to other
plugins but I can't found anythin I can understand :P

Thank you