Warning: mysqli_stmt_bind_param(): Number of variables doesn't match number of parameters in prepared statement even though I have enough number of parameters

[MXP2095onetechguy]

Warning: mysqli_stmt_bind_param(): Number of variables doesn't match number of parameters in prepared statement in C:\wamp64\www\register.php on line 98 but I have enough numbers of parameter here's my code: ` $username = $password = $email = $confirm_password = ""; $username_err = $password_err = $email_err = $confirm_password_err = "";

// Processing form data when form is submitted if($_SERVER["REQUEST_METHOD"] == "POST"){ if (filter_var($email, FILTER_VALIDATE_EMAIL)) { $email_err = "Invalid email format"; } // Validate username if(empty(trim($_POST["username"]))){ $username_err = "Please enter a username."; } else{ // Prepare a select statement $sql = "SELECT id FROM users WHERE username = ?";

    if($stmt = mysqli_prepare($link, $sql)){
        // Bind variables to the prepared statement as parameters
        mysqli_stmt_bind_param($stmt, "s", $param_username);

        // Set parameters
        $param_username = trim($_POST["username"]);

        // Attempt to execute the prepared statement
        if(mysqli_stmt_execute($stmt)){
            /* store result */
            mysqli_stmt_store_result($stmt);

            if(mysqli_stmt_num_rows($stmt) == 1){
                $username_err = "This username is already taken.";
            } else{
                $username = trim($_POST["username"]);
            }
        } else{
            echo "Oops! Something went wrong. Please try again later.";
        }

        // Close statement
        mysqli_stmt_close($stmt);
    }
}

// Validate password
if(empty(trim($_POST["password"]))){
    $password_err = "Please enter a password.";     
} elseif(strlen(trim($_POST["password"])) < 6){
    $password_err = "Password must have atleast 6 characters.";
} else{
    $password = trim($_POST["password"]);
}
// Validate confirm password
if(empty(trim($_POST["confirm_password"]))){
    $confirm_password_err = "Please confirm password.";     
} else{
    $confirm_password = trim($_POST["confirm_password"]);
    if(empty($password_err) && ($password != $confirm_password)){
        $confirm_password_err = "Password did not match.";
    }
}
if(empty(trim($_POST["email"]))){
    $email_err = "Please enter an email.";
} else{
    // Prepare a select statement
    $sql = "SELECT id FROM email WHERE , = ?";

    if($stmt = mysqli_prepare($link, $sql)){
        // Bind variables to the prepared statement as parameters
        mysqli_stmt_bind_param($stmt, "s", $param_email);

        // Set parameters
        $param_email = trim($_POST["email"]);

        // Attempt to execute the prepared statement
        if(mysqli_stmt_execute($stmt)){
            /* store result */
            mysqli_stmt_store_result($stmt);
        } else{
            echo "Oops! Something went wrong. Please try again later.";
        }

        // Close statement
        mysqli_stmt_close($stmt);
    }
}

// Check input errors before inserting in database
if(empty($username_err) && empty($password_err) && empty($confirm_password_err) && empty($email_err)){

    // Prepare an insert statement
    $sql = "INSERT INTO users (username, password) VALUES (?, ?)";

    if($stmt = mysqli_prepare($link, $sql)){
        // Bind variables to the prepared statement as parameters
        mysqli_stmt_bind_param($stmt, "sss", $param_username, $param_password, $param_email);

        // Set parameters
        $param_username = $username;
        $param_password = password_hash($password, PASSWORD_DEFAULT); // Creates a password hash
        $param_email = $email;

        // Attempt to execute the prepared statement
        if(mysqli_stmt_execute($stmt)){
            // Redirect to login page
            header("location: login.php");
        } else{
            echo "Something went wrong. Please try again later.";
        }

        // Close statement
        mysqli_stmt_close($stmt);
    }
}

// Close connection
mysqli_close($link);

} ?>` can you help me tell what is wrong with the code here's my screen: