title: $(window) bind hashchange how to check part hash changed?
body: <p>I am studing <code>Google Ajax Crawlable</code></p>
  
  <p>I use <code>$(window) bind hashchange</code> to control ajax page loading.</p>
  
  <p>my url like:  <code>domain.com/#!/keywords&amp;num=1</code></p>
  
  <p>there has two kind of change </p>
  
  <ol>
  <li><p><code>domain.com/#!/apple&amp;num=1</code> => <code>domain.com/#!/apple&amp;num=2</code></p></li>
  <li><p><code>domain.com/#!/apple&amp;num=1</code> => <code>domain.com/#!/banana&amp;num=1</code></p></li>
  </ol>
  
  <p>so how to check if <code>$(window) bind hashchange</code> changed hash part from <code>apple</code> => <code>banana</code> ? Thanks. </p>
  
  <pre><code>$(window).bind('hashchange', function() {
      // make a judge like  if(){}else{}
  });
  </code></pre>