multi viewcontroller : call variable of root controller from a sub view controller
<pre><code>//root controller
class subviewcontroller;
@rootviewcontroller:UIViewController
{
   NSInteger a;
}
</code></pre>

<p>call a in subviewcontroller
super.a=1;</p>

<p>system reported:</p>

<pre><code>error：Request for member ‘a' in something not a structure or union
</code></pre>

<p>welcome any comment</p>

<p>interdev</p>
