function recalculatePrice() {
  amount = document.getElementsByName("amount")[0].value;
  //pobranie ceny jednostkowej z ukrytego pola formularza
  cena = parseInt(document.forms['order_form'].unit_price.value);
  
  //pobranie waluty z ukrytego pola formularza
  currency = document.forms['order_form'].currency.value;

  //ustalenie ceny calkowitej
  price = parseInt(amount)*cena;

  //stawka vat'u
  var vat=0;
  var vat_price=0;
  try{
	vat = document.forms['order_form'].vat.value;
	vat_price = (vat * price / 100) + price;
	vat_price = vat_price.toFixed(2);

  }catch(err){
  }

  //cena brutto
  
  if (parseInt(price).toString() != "NaN"){
    document.getElementsByName("total_price")[0].value = price+" "+currency;
    document.getElementsByName("price")[0].value = price+" "+currency;
    // w starych formularzach nie ma pola vatu
    try{
      document.getElementsByName("vat_price")[0].value = vat_price+" "+currency;
    }catch(err){
    }
  }
  else {
    document.getElementsByName("total_price")[0].value = "0 "+currency;
    document.getElementsByName("price")[0].value = "0 "+currency;
    // w starych formularzach nie ma pola vatu
    try{
      document.getElementsByName("vat_price")[0].value = "0 "+currency;
    }catch(err){
    }
  }
};

function resetInputs() {
    currency = document.forms['order_form'].currency.value;

    document.getElementsByName("company")[0].checked = false;
    document.getElementsByName("amount")[0].value = "";
    document.getElementsByName("price")[0].value = "0 "+currency;
    document.getElementsByName("price")[0].disabled = true;
    document.getElementsByName("client_name")[0].value = "";
    document.getElementsByName("client_street")[0].value = "";
    document.getElementsByName("client_code")[0].value = "";
    document.getElementsByName("client_city")[0].value = "";
    document.getElementsByName("client_phone")[0].value = "";
    document.getElementsByName("client_email")[0].value = "";
    document.getElementsByName("client_firm_address")[0].disabled = true;
    document.getElementsByName("client_firm_name")[0].disabled = true;
    document.getElementsByName("client_firm_vat_id")[0].disabled = true;
    document.getElementsByName("client_firm_name")[0].value = "";
    document.getElementsByName("client_firm_vat_id")[0].value = "";
    document.getElementsByName("client_firm_address")[0].value = "";
    document.getElementsByName("client_firm_name")[0].style.background = "#DCD8D6";
    document.getElementsByName("client_firm_vat_id")[0].style.background = "#DCD8D6";
    document.getElementsByName("client_firm_address")[0].style.background = "#DCD8D6";
};

function operateInputs(ob) {
  	if (ob.checked) {
  		document.getElementsByName("client_firm_name")[0].disabled = false;
  		document.getElementsByName("client_firm_vat_id")[0].disabled = false;
  		document.getElementsByName("client_firm_address")[0].disabled = false;
  		document.getElementsByName("client_firm_name")[0].style.background = "#e8f6ff";
  		document.getElementsByName("client_firm_vat_id")[0].style.background = "#e8f6ff";
  		document.getElementsByName("client_firm_address")[0].style.background = "#e8f6ff";
  	} else {
  		document.getElementsByName("client_firm_name")[0].disabled = true;
  		document.getElementsByName("client_firm_vat_id")[0].disabled = true;
  		document.getElementsByName("client_firm_address")[0].disabled = true;
  		document.getElementsByName("client_firm_name")[0].value = "";
  		document.getElementsByName("client_firm_vat_id")[0].value = "";
  		document.getElementsByName("client_firm_address")[0].value = "";
  		document.getElementsByName("client_firm_name")[0].style.background = "#DCD8D6";
  		document.getElementsByName("client_firm_vat_id")[0].style.background = "#DCD8D6";
  		document.getElementsByName("client_firm_address")[0].style.background = "#DCD8D6";  		
	}  		
};

function genNo(field) {
  var date = new Date();
  var year = date.getYear();
  if (navigator.appName == "Netscape") year = parseInt(year)+1900;
  year = year.toString();
  var month = (date.getMonth()+1).toString();
  if (month.length < 2) month = "0"+month;
	var day = date.getDate().toString();
	if (day.length < 2) day = "0"+day;
	var hours = date.getHours().toString();
	if (hours.length < 2) hours = "0"+hours;
	var minutes = date.getMinutes().toString();
	if (minutes.length < 2) minutes = "0"+minutes;
	var milisec = date.getMilliseconds().toString();
	var offset = (Math.round(Math.random()*999)).toString();
	var offsetT = "";
	
	if (offset.length < 3) {
		for (var i=0; i < 3-offset.length; i++) offsetT += "0";
	}
	offset = offsetT + offset;
			
	document.getElementsByName(field)[0].value = year+month+day+hours+minutes+milisec+"_"+offset;
	document.getElementsByName(field+".")[0].value = year+month+day+hours+minutes+milisec+"_"+offset;
}