function check_mail(adresa) {
	re = /^[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z]{2,4}$/;
	return adresa.search(re) == 0;
}

// http://www.smartwebby.com/DHTML/phone_no_validation.asp
// Declaring required variables
var digits = "0123456789";
// non-digit characters which are allowed in phone numbers
var phoneNumberDelimiters = "()- ";
// characters which are allowed in international phone numbers
// (a leading + is OK)
var validWorldPhoneChars = phoneNumberDelimiters + "+";
// Minimum no of digits in an international phone no.
var minDigitsInIPhoneNumber = 10;

function isInteger(s) {
	var i;
	for (i = 0; i < s.length; i++) {
		// Check that current character is number.
		var c = s.charAt(i);
		if (((c < "0") || (c > "9")))
			return false;
	}
	// All characters are numbers.
	return true;
}

function stripCharsInBag(s, bag) {
	var i;
	var returnString = "";
	// Search through string's characters one by one.
	// If character is not in bag, append to returnString.
	for (i = 0; i < s.length; i++) {
		// Check that current character isn't whitespace.
		var c = s.charAt(i);
		if (bag.indexOf(c) == -1)
			returnString += c;
	}
	return returnString;
}

function checkInternationalPhone(strPhone) {
	s = stripCharsInBag(strPhone, validWorldPhoneChars);
	return (isInteger(s) && s.length >= minDigitsInIPhoneNumber);
}

function checkform(form) {
	BarvaBg = "#FFCCCC"; // barva pozadi inputu pri bugu
	BarvaBrd = "1px solid #FF0000"; // barva rámecku inputu pri bugu
	BarvaBrdDot = "1px dashed #FF0000"; // splyvava barva rámecku
	BarvaBrdLite = "1px solid #FFCCCC"; // splyvava barva rámecku svetlejsi
	if (form.arrival.value == "") {
		alert("Please fill in your DATE OF ARRIVAL.\nThank you!");
		form.arrival.style.background = BarvaBg;
		form.arrival.style.border = BarvaBrd;
		form.formtop.focus();
		form.arrival.focus();
		return false;
	}

	else if (form.nights.value == "") {
		alert("Please fill in NUMBER OF NIGHTS of your stay.\nThank you.");
		form.nights.style.background = BarvaBg;
		form.nights.style.border = BarvaBrd;
		form.formtop.focus();
		form.nights.focus();
		return false;
	}

	else if (form.persons.value == "") {
		alert("Please fill in NUMBER OF PERSONS.\nThank you.");
		form.persons.style.background = BarvaBg;
		form.persons.style.border = BarvaBrd;
		form.formtop.focus();
		form.persons.focus();
		return false;
	}

	else if (form.name.value == "") {
		alert("Please fill in your FIRST NAME.\nThank you.");
		form.name.style.background = BarvaBg;
		form.name.style.border = BarvaBrd;
		form.formtop.focus();
		form.name.focus();
		return false;
	}

	else if (form.last.value == "") {
		alert("Please fill in your FAMILY NAME.\nThank you.");
		form.last.style.background = BarvaBg;
		form.last.style.border = BarvaBrd;
		form.formtop.focus();
		form.last.focus();
		return false;
	}

	else if (form.email.value == "") {
		alert("Please fill in your VALID EMAIL.\nThank you.");
		form.email.style.background = BarvaBg;
		form.email.style.border = BarvaBrd;
		form.formtop.focus();
		form.email.focus();
		return false;
	}

	else if (form.email.value != "" && !check_mail(form.email.value)) {
		alert("This is NOT VALID EMAIL address.\nPlease fill in your EMAIL address CORRECTLY.\nThank you!");
		form.email.style.background = BarvaBg;
		form.email.style.border = BarvaBrd;
		form.formtop.focus();
		form.email.focus();
		return false;
	}

	else if (form.phone.value == "") {
		alert("Please fill in your TELEPHONE NUMBER.\nMost preferably mobile (cellular) one.\nThank you.");
		form.phone.style.background = BarvaBg;
		form.phone.style.border = BarvaBrd;
		form.formtop.focus();
		form.phone.focus();
		return false;
	}

	else

		var Phone = form.phone;
	if (checkInternationalPhone(Phone.value) == false) {
		alert("Please enter a VALID PHONE NUMBER (in international format).\nThank you.")
		Phone.value = ""
		form.phone.style.background = BarvaBg;
		form.phone.style.border = BarvaBrd;
		form.formtop.focus();
		form.phone.focus();
		return false
	}

	else
		return true;

}

function validatephone(xxxxx) {
	var maintainplus = '';
	var numval = xxxxx.value
	if (numval.charAt(0) == '+') {
		var maintainplus = '+';
	}
	curphonevar = numval.replace(
			/[\\A-Za-z!"L$%^&*+_={};:'@#~,.¦\/<>?|`¬\]\[]/g, '');
	xxxxx.value = maintainplus + curphonevar;
	var maintainplus = '';
	xxxxx.focus;
}