Find out whether radio button is checked with JQuery?

Question

I can set a radio button to checked fine, but what I want to do is setup a sort of 'listener' that activates when a certain radio button is checked.

Take, for example the following code:

$("#element").click(function()
{ 
    $('#radio_button').attr("checked", "checked");
});

it adds a checked attribute and all is well, but how would I go about adding an alert. For example, that pops up when the radio button is checked without the help of the click function?

Answer 1

$('#element').click(function() {
   if($('#radio_button').is(':checked')) { alert("it's checked"); }
});