<select id="payment-method" onchange="showInput()">
<option value="">Lütfen bir ödeme yöntemi seçin</option>
<option value="credit-card">Kredi kartı</option>
<option value="havale-eft">Havale-EFT</option>
<option value="paypal">PayPal</option>
</select>
<input type="text" id="havale-eft-info" style="display:none" placeholder="Havale-EFT bilgileri">
<script>
function showInput() {
var paymentMethod = document.getElementById("payment-method");
var havaleEftInfo = document.getElementById("havale-eft-info");
if (paymentMethod.value === "havale-eft") {
havaleEftInfo.style.display = "block";
} else {
havaleEftInfo.style.display = "none";
}
}
</script>