错误在注册系统的用户- PHP


Bug in the registration system for users - PHP

我通过驻留在不同页面中的表单"POST"为用户注册编写了这个脚本。脚本可以工作,设法捕获数据,但是当过程完成时,用户表I没有获得添加的用户。就好像从来没有人进去过一样。即使填写所有可用的字段,表仍然是空的,我会知道原因,并说明什么是错的?

$dbconnect = new MySQLi(HOST, USER, PASSWORD, DATABASE);
mysqli_stmt_bind_param($dbconnect, "????", $name, $surname, $password, $admin);
$sql = "INSERT INTO user (name, surname, password, admin)
VALUES (?, ?, ?, ?)";
if (mysqli_query($dbconnect,$sql)) 
{
?>
<script>
    fadeInPopup();
    popupMessage.text("User add!");
</script>
<?php
}   
else
    {
?>
<script>
    fadeInPopup();
    popupMessage.text("Error: " . mysqli_error($dbconnect););
</script>

This This:

else
    {
?>
<script>
    fadeInPopup();
    var er = '<?php mysqli_error($dbconnect);?>';
    popupMessage.text("Error: "+er);
</script>