Dashcode newbie: Change a button's label programmatically

Question

I'm new to Mac OS X Dashboard developement. Now, I have a button with id b_start. When that button is clicked, I want the label of the button to change to "Round".

Now I have tried these, but none of them work:

document.getElementById("b_start").label = "Round";
document.getElementById("b_start").text = "Round";
document.getElementById("b_start").innerText = "Round";
document.getElementById("b_start").object.setValue("Round");
document.getElementById("b_start").value = "Round";

Does anyone how I can change the button's label?

Answer 1

I solved the question my own. Just use this:

document.getElementById("b_start").object.textElement.innerText = "Round";

Answer 2

document.getElementById("b_start").object.setText("Round");

Answer 3

document.getElementById("b_start").object.setEnabled(false);