function currencyExchange(form){
	var exchangeRate = 0.11;
	var amount = form.amount.value;

	if(amount == ""){
		alert("請輸入銀碼");
		form.amount.focus();
		return false;
	}
	else{
		if(form.currency.value == "HKD"){
			form.resultAmount.value = ("$ "+ Math.round(amount / exchangeRate)+" JPY");
			return false;
		}
		else{
			form.resultAmount.value = ("$ "+ Math.round(amount * exchangeRate)+" HKD");
			return false;
		}
	}
}