Add attribute and clear attribute : attr « jQuery « JavaScript Tutorial

<html>
  <head>
    <script type='text/javascript' src='js/jquery-1.3.2.js'></script>
    <script type='text/javascript'>
$(document).ready(
  function() {
    $('div').hover(
      function() {
        $(this).attr('id', 'justAdd');
        $(this).text('This element\'s ID is: ' + $(this).attr('id'));
      },
      function() {
        $(this).attr('id', '');
        $(this).text('This element\'s ID has been removed.');
      }
    );
  }
);

$('a').removeAttr('title');
    </script>
    <style type='text/css'>
div {
    width: 350px;
    padding: 10px;
    border: 1px solid rgb(200, 200, 200);
    background: #93cdf9;
    margin: 5px;
}
div#justAdd {
    background: #6faddd;
}
    </style>
  </head>
  <body>
     <div>Mouse over to change this element's id.</div>
  </body>
</html>

30.18.attr
	30.18.1.	Disable input control
	30.18.2.	Get attribute from tag
	30.18.3.	Get input control type
	30.18.4.	Set Image URL title alt
	30.18.5.	attr(key, fn)
	30.18.6.	Sets src attribute from title attribute on the image.
	30.18.7.	attr(key, value) set a single property to a value, on all matched elements.
	30.18.8.	Finds the title attribute of the first in the page.
	30.18.9.	attr(name): access a property on the first matched element.
	30.18.10.	Disable all form input controls
	30.18.11.	Add attribute and clear attribute
	30.18.12.	Set attribute with the returned function value