kindasortanotreally, there's better ways of doing it though prototype but they're not really needed here and add no real capabilities. I mean I could redefine obj.test as needed and call it directly but unless I need to pass variables with the function, there's no advantage.
Code:
var obj = new Object();
obj.test = function() {
alert("working!");
}
obj.run(param) {
//do something interesting here
param; //execute param, in theory.
//do something interesting here as well
param //maybe call it again.
}