Hola Mousi,
aquí tienes un ejemplo:
Código PHP:
$noneSelected=$visaSelected=$mastercardSelected=$deltaSelected=$soloSelected=$switchSelected="";
if (isset($_POST['paymentMethod'])) {
switch ($_POST['paymentMethod']) {
case "1":
$visaSelected = "selected";
break;
case "2":
$mastercardSelected = "selected";
break;
case "3":
$deltaSelected = "selected";
break;
case "4":
$soloSelected = "selected";
break;
case "5":
$switchSelected = "selected";
break;
}
} else {
$noneSelected = "selected";
}
$html = <<<EOT
<select name="paymentMethod">
<option value="0" $noneSelected></option>
<option value="1" $visaSelected>Visa</option>
<option value="2" $mastercardSelected>Mastercard</option>
<option value="3" $deltaSelected>Delta (Visa Debit)</option>
<option value="4" $soloSelected>Solo</option>
<option value="5" $switchSelected>Switch</option>
</select>
EOT;