Alert Box does not Pop up
<p>I am new to jQuery and presently reading jquery for dummies,and was trying to execute first example of the book:</p>

<pre><code>&lt;!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Strict//EN”  
“http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd”&gt;  
&lt;html&gt;  
&lt;head&gt;  
&lt;title&gt;My Test Page&lt;/title&gt;  
&lt;script type="text/javascript" src="js/jquery-1.7.2.js"&gt;  
$(document).ready(function(){  
alert(jQuery(‘img’).attr(‘alt’));  
});  
&lt;/script&gt;  
&lt;/head&gt;  
&lt;body&gt;  
&lt;p&gt;This is my test page.&lt;/p&gt;  
 &lt;img src= "images/home.gif" height="28" width="28" alt="This is a test  
image."&gt;  
&lt;/body&gt;  
&lt;/html&gt;   
</code></pre>

<p>But after executing this example,the alert box does not pop-up.</p>
