help using password instead of gravatar

i am using jquery chat tutorial

for chatting. I am working on this to make registration separately using a username and password.

Right now it is taking username and gravatar for registration. I changed my code for regist开发者_开发知识库ration. But if it gets a username in the database, it just updates its timestamp and password leaving the username unchanged. But i want to show error if the username already exists. How can i achieve this goal?

Also it is deleting the user from database after some time of idle state. How can i remove this functionality?

Set the name field in webchat_users to unique. Or insert following lines of code into your PHP class:

$userEnteredName = 'John';
$row = mysql_fetch_assoc(DB::query("SELECT `name` FROM `webchat_users` WHERE `name` LIKE '".mysql_real_escape_string($userEnteredName)."' LIMIT 1"));
if(!empty($row['name'])) {
    // Username taken
    die('Username taken.');
} else {
    // Proceed registration.
}

For your second problem: Simply remove line 33 & 34 from Chat.class.php.