$mydb = new mysqli('localhost', 'username', 'password', 'databasename');
$sql = "INSERT INTO users (fname, lname, comments)
VALUES ('$_POST[fname]', '$_POST[lname]', '$_POST[comments]')";
if ($mydb->query($sql) == TRUE) {
echo "user entry saved successfully.";
} else {
echo "INSERT attempt failed" ;
}
$mydb->close();