新手求助，用php无法把数据插入数据库

[竹果菌]

自学做一个网页的登录注册，但注册时输入的用户名及密码无法插入到数据库的表里，不知道该怎么办
下面是我的代码

<?php

error_reporting(0);
if (isset($_POST["Submit"]) && $_POST["Submit"] == "Submit") {
$user = $_POST["username"];
$psw = $_POST["password"];
$psw_confirm = $_POST["confirm"];
echo $user;
if ($user == "" || $psw == "" || $psw_confirm == "") {
echo "<script>alert('Make sure that the integrity of the information！'); history.go(-1);</script>";
}
else {
if ($psw == $psw_confirm) {
$dbhost = 'localhost:3308'; // mysql服务器主机地址
$dbuser = 'root'; // mysql用户名
$dbpass = ''; // mysql用户名密码
$conn = mysqli_connect($dbhost, $dbuser, $dbpass);
if(! $conn )
{
die('连接失败: ' . mysqli_error($conn));
}
echo '连接成功<br />';

mysqli_query($conn , "set names utf8");



if ($psw == $psw_confirm) {
echo $user;
echo $psw;
$sql = "INSERT INTO account ".
"(user,psw) ".
"VALUES ".
"('$user','$psw')";


$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
die('无法插入数据: ' . mysqli_error($conn));
}
echo "数据插入成功\n";
mysqli_close($conn);
} else {
echo "<script>alert('两次输入密码不一致！')</script>";
}


}
else{
echo "<script>alert('Inconsistent password！'); history.go(-1);</script>";
}

}
}
else
{
echo "<script>alert('Submission Failed！'); history.go(-1);</script>";
}
?>

[竹果菌]

这是我的数据库，服务器没有密码

[snlixing]

$sql = "INSERT INTO account (user,psw) VALUES ('".$user."','".$psw."')";