Find out if a Variable exists
<p>I would like to find out if a Javascript variable exists. This is what I have so far which was cobbled together from different forums:</p>

<pre><code>function valueOfVar(foo){

    var has_foo = typeof foo != 'undefined';

    if(has_foo){
        alert('1 = true');
        return true;
    }
    else {
        alert('1 = false');
        return false;
    }

}
</code></pre>

<blockquote>
  <p>Please note, I wish to pass in a
  string as foo. Example: valueOfVar(box_split[0]+'_2')</p>
</blockquote>

<p>Now, I don't think this works because it returns true when certain variables don't even exist. In fact, it seems to return true all the time.</p>

<p>A JQuery implementation that works would also be great as I make use of this.</p>

<p>Thanks all for any help</p>
