I am using the below script for my website.
I got a error saying

Fatal error: Call to undefined function: session_pagestart() in /home/somplan/public_html/test1.php on line 7

PHP Code:

 <?php
 
 $phpbb_root_path = '/home/somplan/public_html/forums/';
 
 include($phpbb_root_path . 'common.php');
 
 $userdata = session_pagestart($user_ip, PAGE_INDEX);
 init_userprefs($userdata);
 
 if ( $userdata['session_logged_in'] ) {
 $username = $userdata['username'];
 echo "Welcome $username"; } else {
 echo('
 Forum Login
 
 <form action="http://www.somplanet.com/forums/login.php" method="post" target="_top">
 
 Username: <input type="text" name="username" size="25" maxlength="40" value="" />
 
 Password: <input type="password" name="password" size="25" maxlength="32" />
 
 <input type="hidden" name="redirect" value="" /><input type="submit" name="login" class="mainoption" value="Log in" />
 
 </form>');
 }
 ?>

There is no function session_pagestart() in php, it must be some external function. So you probably forgot to include the file with this function's definition.

By the way this script is for a PHPBB forums. Does anyone know what is wrong.

Either you have erased an include line from the file, or this:

PHP Code:

 $phpbb_root_path = '/home/somplan/public_html/forums/';

include($phpbb_root_path . 'common.php'); 


isn't finding the file it needs.