What is proper way to calling session_start()
<p>I have two shared host.
my problem is realated with calling session_start().
In my localhost and one of my shared host. session start works well with user notice that : cannot call header. then i used to write the below code:</p>

<pre><code>&lt;?php
if(! isset($_SESSION)){
 session_start()
}
?&gt;
</code></pre>

<p>But in another host, it still echo message that <strong>"Notice: cannot start session()..."</strong>
also my problem that session doesn't starts in first visit. When I refresh my browser window again then starts session. what is relation between client and server side. again what is wrong with my session_start() ? please help me.</p>

<p>May anyone tell me that what is the proper way to calling a session_start() which will never fail. and where should I call. very top of the page or anywhere in the configuration file. a little example will help me surely.</p>
