How to know if a session has been set
<p>In php i used to use </p>

<pre><code>session_start();
if(isset(SESSION["user"]))
{
   //session is set
}
els{
    // there is no session 
}
</code></pre>

<p>but do i do that in asp.net? I mean. What code can tells wheather a session is set or not</p>

<p>ex:
asp.net c#</p>

<pre><code>//login.aspx
SESSION["USER"];

//user_profile.aspx
if(SESSION["USER"])// how do i validate that??
{

}
</code></pre>
