我的插入查询只执行一次

Question

我有一个注册页面，当第一个用户注册时，它可以正常工作。当第二个用户注册INSERT查询时输出错误。这是我的代码：

if ($err_found != true)
    $saveData = "INSERT INTO anc_user_info (CardNumber, UserName, Password, Name, 
                         Surname, IDNumber, Province, Region, Branch, Gender, Language, 
                         PhysicalAddress, Profession, Category, TelNoW, TelNoH, Email, 
                         Cell, ProfilePic, TransactionRef, DepositAmount, DepositerName, 
                         Declaration, UserID, Status, CreateDate) 
            VALUES( '$CardNumber', '$UserName', md5('$Password'), '$Name', '$Surname', 
                        '$IDNumber', '$Province', '$Region', '$Branch', '$Gender', 
                        '$Language', '$PhysicalAddress', '$Profession', '$Category', 
                        '$TelNoW', '$TelNoH', '$Email', '$Cell', '$ProfilePic', 
                        '$TransactionRef', '$DepositAmount', '$DepositerName', 
                        '$Declaration', '$UserID', 0, NOW())" ;