i have a sign up forum that i dont want the users to have spaces in their user name.
it will go to an error page if a field is blank.can i add something so it will do the same if the user name has a space?

PHP Code:

if ($_POST['do'] == 'setup')
{
    if (empty($_POST['name'])
    {
        print_error_message($lang['error']);
    } 


I'm sure you can manipulate this for what you need...

PHP Code:

<?php
$user1 = "Mighty Mouse";
$user2 = "Mighty_Mouse";

if(eregi("[ \t]", $user1)) {
   echo "$user1: contains a space or tab!<br>";
} else {
    echo "$user1: Does NOT contain a space or a tab!<br>";
}

if(eregi("[ \t]", $user2)) {
   echo "$user2: contains a space or tab!<br>";
} else {
    echo "$user2: Does NOT contain a space or a tab!<br>";
}
?>

Easiest thing to do is to use some regex (you could use just a strpos(), but regex is easily expanded if you want to limit to other chars in the future).

PHP Code:

if ($_POST['do'] == 'setup')
{
    $_POST['name'] = trim($_POST['name']);

    if (empty($_POST['name']) || !preg_match('#^([^ ]+)$#', $_POST['name']))
    {
        print_error_message($lang['error']);
    } 


Or better yet, just use regex to explicitly set the acceptable chars:

PHP Code:

<?php

if ($_POST['do'] == 'setup')
{
    $_POST['name'] = trim($_POST['name']);

    if (empty($_POST['name']) || !preg_match('#^([a-zA-Z0-9\-_]+)$#', $_POST['name']))
    {
        print_error_message($lang['error']);
    }

^ Will allow only letters (a-z), numbers, hyphens and underscores.