function checkStrings(valid,check) {
	var checkOK = valid;
	var checkStr = check;
	var allValid = true;

	for (var i = 0; i < checkStr.length; i++) {
		var ch = checkStr.charAt(i);
		if (checkOK.indexOf(ch) == -1) {
			allValid = false;
			break
		}
	}
	return(allValid)
}

function isValidCharacters(field) {
	var checkOK = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
	var checkStr = field.value;

	if (checkStr.length > 0)
		return(checkStrings(checkOK, checkStr));
	return false
}

function isValidAlphaNumericCharacters(field) {
	var checkOK = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 "
	var checkStr = field.value;

	if (checkStr.length > 0)
		return(checkStrings(checkOK, checkStr));
	return false
}

function isValidAddress(field) {
	var checkOK = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 " + validSpecialCharacters()
	var checkStr = field.value;

	if (checkStr.length > 0)
		return(checkStrings(checkOK, checkStr));
	return false
}

function isValidNumbers(field) {
	var checkOK = "0123456789"
	var checkStr = field.value;
	
	if ((checkStr.length > 0) && (checkStr > 0))
		return(checkStrings(checkOK, checkStr));
	return false
}

function isValidPhoneNumber(field) {
	var checkOK = "+- ()0123456789"
	var checkStr = field.value;
	
	if (checkStr.length > 0)
		return(checkStrings(checkOK, checkStr));
	return false
}

function isValidEmail(email) {
	var exclude=/[^@\-\.\w]|^[_@\.\-]|[\._\-]{2}|[@\.]{2}|(@)[^@]*\1/;
	var check=/@[\w\-]+\./;
	var checkend=/\.[a-zA-Z]{2,3}$/;

	if(((email.search(exclude) != -1)||(email.search(check)) == -1)||(email.search(checkend) == -1))
		return false;
	return true
}

function isValidSelection(field) {
	if (field.type != "select-one") {
		return false
	}
	else {
		if (field.selectedIndex == 0)
			return false;
	}
	return true
}

function isValidFutureDate(refdate,date) {
	var NowDate = new Date(refdate);
	var TestDate = new Date(date);
	
	if (NowDate > TestDate)
		return false;
	return true
}

function isValidDates(datepast,datefuture) {
	var PastDate = new Date(datepast);
	var FutureDate = new Date(datefuture);
	
	if (PastDate > FutureDate)
		return false;
	return true
}

function validSpecialCharacters() {
	var chars = String.fromCharCode(9,10,13);
	return(chars)
}