get id via jQuery attr

by planetoid

HTML

<form>
First name: <input type="text" id="111" name="firstname"><br />
Last name: <input type="text" id="222" name="lastname"><br />
<button type="button" id="btn">Click Me!</button> 
</form>

JavaScript

$("button").click(function(){
  $("#222").attr("id");
  alert("id is " + $("#222").attr("id"));  
});