Te sobra la ultima coma
Código PHP:
<?php
$state = false;
if ($_POST['action'] == "add") {
$conexion = mysql_connect("localhost", "usuario", "password_db");
mysql_select_db("base_de_datos", $conexion);
$que = "INSERT INTO smf_members (memberName, realName, passwd, emailAddress) ";
$que.= "VALUES ('".$_POST['memberName']."', '".$_POST['realName']."', '".$_POST['passwd']."', '".$_POST['emailAddress']."') ";
$res = mysql_query($que, $conexion) or die(mysql_error());
$state = true;
}
?>
1 saludo