function CheckForm() {
	if (Subtotal_P==0) {
		alert('Total deposit amount is 0');
		return false;
	};
	with (document.f_visible) {
		if (LastName.value.length < 2) {LastName.focus(); alert('Last name - 2 letters minimum'); return false};
		if (FirstName.value.length < 2) {FirstName.focus(); alert('First name - 2 letters minimum'); return false};
		if (City.value.length < 7 || City.value.indexOf(",") < 0) {
			City.focus();
			alert('Country, City - 7 letters minimum, comma separated');
			return false;
		};
		if (Email.value.length < 6 && Phone.value.length < 7) {
			alert('Phone number or email address required')
			return false;
		};
		if (Email.value.length > 5 && (Email.value.indexOf("@") < 0 || Email.value.indexOf(".") < 0)) {
			alert('Error in email address - format: name@server.xxx');
			Email.focus();
			return false;
		};
	};
	with (document) {
		f_hidden.LastName.value = f_visible.LastName.value;
		f_hidden.FirstName.value = f_visible.FirstName.value;
		f_hidden.MiddleName.value = f_visible.MiddleName.value;
		f_hidden.City.value = f_visible.City.value;
		f_hidden.Phone.value = f_visible.Phone.value;
		if (f_visible.Email.value.length > 5) {
			f_hidden.Email.value = f_visible.Email.value;
		} else {
			f_hidden.Email.value = 'net@net.net';
		};

		f_hidden.submit();
	};
};
/*
function CalcSum() {
	var i = 0;
	var Subtotal_P = 0;
	var Comment = "";
	for (i=0; i<RoomTypes.length; i++) {
		eval("if (document.f_visible.count"+i+".value != '') {Subtotal_P += parseInt(document.f_visible.count"+i+".value)*RoomTypes[i].price}");
		eval("Comment += (i+1)+') '+RoomTypes[i].type+': '+parseInt(document.f_visible.count"+i+".value)+' шт. €'+RoomTypes[i].price+' за шт. '");
	};
	Subtotal_P = parseInt(Subtotal_P);
	if (isNaN(Subtotal_P)) {
		Subtotal_P = 0;
		alert("Неправильно указано количество. Нужно ввести целое число больше 0");
		document.f_visible.SubmitButton.disabled = 1;
	} else {
		document.f_visible.SubmitButton.disabled = "";
	};
	window.Subtotal_P.innerHTML = "€"+Subtotal_P;
	document.f_hidden.Subtotal_P.value = Subtotal_P;
	document.f_hidden.Comment.value = Comment;
	return Subtotal_P;
};   */

function CalculateSum(price){

  var Comment = "";
  if(sign==0){
    Subtotal_P += price;
  }
  else{
    Subtotal_P -= price;
  }
  if(Subtotal_P<0){Subtotal_P=0;}

  document.getElementById("total_P").innerHTML = '€'+Subtotal_P;
  document.f_hidden.Subtotal_P.value = Subtotal_P;
  document.f_hidden.Comment.value = Comment;
  return Subtotal_P;
}

function Change_sign(new_sign){
  if(sign==new_sign){return false;}
  sign = new_sign;
  if(sign==0){
    document.getElementById("plus").className = 'enabled';
    document.getElementById("minus").className = 'disabled';
  }
  else{
    document.getElementById("plus").className = 'disabled';
    document.getElementById("minus").className = 'enabled';
  }
}

function to_Null(){
  Subtotal_P=0;
  CalculateSum(0);
}

var Subtotal_P = 0;
var sign = 0;

/*
document.write("<table>");
for (i=0; i<RoomTypes.length; i++) {
	document.write("<tr><td class=\"td1_3\">"+RoomTypes[i].type+":</td><td class=\"formfield\"> <input size=3 name=count"+i+" value=0 onkeyup=CalcSum() /></td><td class=\"td3_2\"> шт (предоплата за шт. €"+RoomTypes[i].price+")</td></tr><tr><td colspan=\"3\" class=\"td3_2\"></td></tr>");
};
document.write("</table>");    */