timeout

Hi, below is a script that accepts a username and password and after accepting them, displays another form. I need to timeout the user after a specific amount of time using sessions,eg,30 seconds, and display a warning.Can anyone help me to do that?



<?php

if(!isset($_POST['submit1']) && !isset($_POST['submit2']))
{
?>
<form action="s9.php" method="post">

Name:<input type="textfield" name="username">

Password: <input type="password" name="password">

<input type="submit" name="submit1" value="Log in">
</form>

<?
}
?>

<?
if(isset($_POST['submit1']))
{

$name=$_POST['username'];
$password=$_POST['password'];

?>

<form action="s9.php" method="post">

Full Name:<input type="textfield" name="fname">

City: <input type="textfield" name="city">

Phone no: <input type="textfield" name="phone">

<input type="submit" name="submit2" value="View details">

<?
}
?>

<?
if(isset($_POST['submit2']))
{
$fname=$_POST['fname'];
$city=$_POST['city'];
$phone=$_POST['phone'];
echo ("
$fname");
echo ("
$city");
echo ("
$phone");
}
?>