Hi my friend,i wrote two classed on is user,the other is db .The user have a property which from the db class object . When i writing my application have both class object invoked at the same time ,just like $user_a = new user($para); $db_a = new db() Then the problem occurs only one of the class object could work, or $user_a or $db_a not both,What 's problem of my code The following is my source code: class db{ /** * Constructor */ var $result; var $conn; function db(){ require_once BOC_BASE_DIR.'/config/db.config.inc'; $this->conn = mysql_connect($db_host,$db_user,$db_pass); //$this->conn = @mysql_connect($db_host,$db_user,$db_pass); if (!$this->conn) { $this->db_print_error("DB connect failed"); } if (!mysql_select_db($db_name,$this->conn)) { $this->db_print_error("DB select failed"); } } class user{ private $u_sn; private $u_id; private $u_name; private $u_sex; private $u_image; //more property private $u_info; /** * Constructor */ function __construct($name){ $sql = "select * from boc_user where u_name = '$name'"; $u_query = new db(); $this->u_info = array(); $u_query->db_query($sql); $this->u_info =$u_query->db_fetch_row(); $this->u_sn = $this->u_info['u_sn']; $this->u_id = $this->u_info['u_id']; $this->u_name = $this->u_info['u_name']; $this->u_sex = $this->u_info['u_sex']; //more are give the property value } The two class works well in the single application when only of them are invoked ,i cost me much time to deal it Any advice and suggestions are thankful ! All you best ------------------------ What we are struggling for ? The life or the life ? -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php