我加了验证码，就注册不了，返回的$row=insert("imooc_user",$arr);函数的id为0

function reg(){

$arr=$_POST;

$arr['password']=md5($_POST['password']);

$arr['regTime']=time();

$path="./uploads/userFace";

$uploadFile=uploadFile($path);

print_r($uploadFile);

// $verify=$_SESSION['verify'];

// $verify1=$_POST['verify'];

// if(strtolower($verify)==strtolower($verify1)){

if($uploadFile&&is_array($uploadFile)){

$arr['face']=$uploadFile[0]['name'];

}else{

return "注册失败";

}

//print_r($arr);exit;

$row=insert("imooc_user",$arr);

print_r($row);

if($row){

$mes="注册成功!<br/>3秒钟后跳转到登陆页面!<meta http-equiv='refresh' content='3;url=login.php'/>";

}else{

$filename=$path."/".$uploadFile[0]['name'];

if(file_exists($filename)){

unlink($filename);

}

$mes="注册失败!<br/><a href='reg.php'>重新注册</a>|<a href='index.php'>查看首页</a>";

}

// }else{

// return "验证码错误!<br/>3秒钟后跳转回注册页面!<meta http-equiv='refresh' content='3;url=reg.php'/>";

// }

return $mes;

}