&& statement javascript not evaluated
<p>I try to write javascript code for OS detection. 
I use navigator.appVersion to generate a variable and then evaluate it. The I use indexOf on that variable for evaluation on a if else statement.
Using string variables like "Windows", "Linux", "iPhone", ..... i evaluate the OS.
On Android phones I observed that navigator.appVersion return something like this:</p>

<p>"5.0 (Linux; U; Android .....)"</p>

<p>so I generated this code to resolve the problem:</p>

<pre><code>&lt;script type="text/javascript"&gt;
        var Windows="Windows";
        var Safari="Safari";
var OSName=navigator.appVersion;
alert(OSName);
function OS() {
if (OSName.indexOf(Linux)!=-1 &amp;&amp; OSName.indexOf(Android)!=-1) {
        alert("Goooood");
} else {
    alert("Baddddd");
    }
}
&lt;/script&gt;
</code></pre>

<p>The thing is that the &amp;&amp; does not evaluate (returns Baddddd...).</p>

<p>Any clue would help.</p>
