Help with commas in RealChat rooms string

[Boofo]

Could anyone please help me add commas to the string of RealChat rooms that the following code generates?

PHP Code:

// REALCHAT WHO'S ONLINE
$port = 10010;
function getServerAPI( $apiCommand ) {
global $port;
$result = "";
$fp = fsockopen("localhost", $port, &$errno, &$errstr, 2);
if(!$fp) {
echo "$errstr ($errno)\n";
} else {
fputs($fp,"GET /?".$apiCommand." HTTP/1.0\n\n");
$header = true;
while(!feof($fp)) {
$line = fgets($fp,128);
if ( $header == false ) $result .= $line;
if ( trim($line) == "" ) $header = false;
}
fclose($fp);
}
return $result;
}
$userCount = getServerAPI( "api.UserCount" );
$roomList = getServerAPI( "api.RoomList" );
// End REALCHAT WHO'S ONLINE 


Right now it looks like this:

Available RealChat Rooms: The Bear's Den The Lobby Fun Staff only! No topic Bear's Den

The rooms are:

The Bear's Den
The Lobby
Fun
Staff only!
No topic
Bear's Den

I would like commas after the names except for the last one.

This is the code that came with it so I have no idea how to add the commas.

Thanks in advance.