准备好的查询在尝试查找用户时未返回预期结果

当我在phpMyAdmin:中这样做时，我得到了一个结果

SELECT password, block FROM jml_users WHERE username = "user01" 

然而，在我的PHP代码中，脚本找不到我的用户。我的$stmt->bind_param("s", $unsafe_user);有什么问题吗？

我也尝试过$stmt->bind_param("s", "user01");，但没有成功。

<?
include("dbinfo.php");
$unsafe_user = "user01";
$mysqli = new mysqli($loginURL, $dbusername, $dbpassword, $database);
LoginCheck();
// Kill connection 
$thread_id = $mysqli->thread_id;    // determine our thread id 
$mysqli->kill($thread_id);
$mysqli->close();
function LoginCheck()
{
    global $mysqli, $unsafe_user;   
    //Perpare Statement.    
    //if($stmt = $mysqli->prepare("SELECT password, block FROM jml_users WHERE (username) VALUES (?)")) // this returns false for some reason
    if($stmt = $mysqli->prepare("SELECT password, block FROM jml_users WHERE username = ?")) //works, still safe form sql injection?
    {
        $stmt->bind_param("s", $unsafe_user);
        $stmt->execute();
        $stmt->bind_result($dbpw, $bdblock);
        if($stmt->num_rows == 0)
        {
            echo "could not find user";
        }
        // Found user
        else
        {
            echo "found user";
        }
        $stmt->close();
    }
    else
    {
        echo "Statement creation did not succeed";
    }
}
?>