Someone

<script language="JavaScript">
<!-- 
function Show_Stuff(Click_Menu)
// Function that will swap the display/no display for 
// all content within span tags
{
if (Click_Menu.style.display == "none")
{
Click_Menu.style.display = "";
}
else
{
Click_Menu.style.display = "none";
}
}
-->
</script>

echo "
<select onchange=\"javascript:Show_Stuff(this.options[this.selectedIndex].value);\" size=2>
<option value=\"wiretransfer\" selected>Automatic Wire Transfer (Belgium Only)</option>
<option value=\"creditcard\">Credit Card</option>
</select><br>

<span id=\"wiretransfer\" style=\"display: none;\">Your account number: <input id=\"wiretransfer\" type=\"text\" size=\"20\" /></span>

<span id=\"creditcard\" style=\"display: none;\">Credit Card</span>

";