function user_modify($username,$attributes){
        if ($username==NULL){ return ("Missing compulsory field [username]"); }
        if (array_key_exists("password",$attributes) && !$this->_use_ssl){ echo ("FATAL: SSL must be configured on your webserver and enabled in the class to set passwords."); exit(); }
        //if (array_key_exists("container",$attributes)){
            //if (!is_array($attributes["container"])){ return ("Container attribute must be an array."); }
            //$attributes["container"]=array_reverse($attributes["container"]);
        //}

        //find the dn of the user
        $user=$this->user_info($username,array("cn"));
        if ($user[0]["dn"]==NULL){ return (false); }
        $user_dn=$user[0]["dn"];

        //translate the update to the LDAP schema				
        $mod=$this->adldap_schema($attributes);
        if (!$mod){ return (false); }
        
        //set the account control attribute (only if specified)
        if (array_key_exists("enabled",$attributes)){
            if ($attributes["enabled"]){ $control_options=array("NORMAL_ACCOUNT"); }
            else { $control_options=array("NORMAL_ACCOUNT","ACCOUNTDISABLE"); }
            $mod["userAccountControl"][0]=$this->account_control($control_options);
        }

        //do the update
        $result=ldap_modify($this->_conn,$user_dn,$mod);
        if ($result==false){ return (false); }
        
        return (true);
    }