insert.php

<?php

$servername = "localhost:8889";
$username = "root";
$password = "root";
$dbname = "Forms";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

$sql1 = "INSERT INTO Users1 (username, password, firstname, surname, address, postcode, email, phone, birthday, birthmonth, birthyear, gender)
VALUES ('$_POST[username]','$_POST[password]','$_POST[firstname]','$_POST[surname]','$_POST[address]','$_POST[postcode]','$_POST[email]','$_POST[phone]','$_POST[birthday]','$_POST[birthmonth]','$_POST[birthyear]','$_POST[gender]')";

$sql2 = "INSERT INTO Currencies1 (email, camount, currency)
VALUES ('$_POST[email]','$_POST[camount]','$_POST[currency]')";

// First connection for user data
if ($conn->query($sql1) === TRUE) {
    echo "Victorrry!";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

// Second connection for currencies
if ($conn->query($sql2) === TRUE) {
    echo "";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$chkbox = $_POST['chk'];
$txtbox = $_POST['camount'];
$country = $_POST['currency'];

foreach($txtbox as $a => $b)
  echo "$chkbox[$a]  -  $camount[$a]  -  $currency[$a] <br />";

$conn->close();
?>

<?php