var formatNumber = /^\d+$/;							// A number contains only digits
var formatHouseNumber = /^\d+$/;					// HouseNumber format starts with a digit
var formatPostalCode = /^(\d{4})\s*([a-z]{2})$/i;	// PostalCode format is 4 digits, possibly some blanks, and 2 letters
var formatEmail = /^[^@\s]+\@[^@\s]+\.[^@\s]+/;		// E-mail is x@x.x
var formatPhone = /^\d{2,4}[ -]{0,1}\d{6,8}$/;		// A phonenumber is formated nn-nnnnnnnn or nnn-nnnnnnn or nnnn-nnnnnn
var formatPhone = /^\d{10}$/;		// A phonenumber is formated nn-nnnnnnnn or nnn-nnnnnnn or nnnn-nnnnnn
var formatDate = /^([0-3]{1}[0-9]{1})(\/|-)([0-1]{1}\d{1})(\/|-)([1]{1}[9]{1}\d{2})$/;	// A date is formated dd/mm/jjjj (or dd-mm-jjjj) with only digits

function trim(strText) { 
    // this will get rid of leading spaces 
    while (strText.substring(0,1) == ' ') 
        strText = strText.substring(1, strText.length);

    // this will get rid of trailing spaces 
    while (strText.substring(strText.length-1,strText.length) == ' ')
        strText = strText.substring(0, strText.length-1);

   return strText;
} 

function textboxFilled(Field, errorMessage) {
	var value = Field.value;
	value = trim(value);
	if (value == "" ) {
		alert(errorMessage);
		Field.focus();
		return false;
	}
	return true;
}

function isValidPhone(Field, errorMessage) {
	var value = Field.value;
	var format = formatPhone;
	if (value !== "") {
		value = value.replace("-","");		
		value = trim(value);
		if (! formatNumber.test(value)) {
				alert(errorMessage);
				Field.focus();
				return false;
		}
		if (! format.test(value)) {
				alert(errorMessage);
				Field.focus();
				return false;
		}
		return true;
	}
	return true;
}

function hiddenFilled(Field, errorMessage) {
	var value = Field.value;
	if (value == "") {
		alert(errorMessage);
		return false;
	}
	return true;
}

function radioChecked(radioGroup, errorMessage) {
	var i;
	for (i = 0; i < radioGroup.length; i++) {
		if (radioGroup[i].checked) {
			radioGroup[i].focus;
			return true;
		}
	}
	alert(errorMessage);
	return false;
}

function checkboxChecked(checkboxGroup, errorMessage) {
	if(checkboxGroup.checked) {
		return true;
	}
	return radioChecked(checkboxGroup, errorMessage);
}

function isNumber(numberField, errorMessage) {
	var value = numberField.value;
	if (! formatNumber.test(value)) {
		alert(errorMessage);
		return false;
	}
	return true;
}

function isLength(numberField, length, errorMessage) {
	var value = numberField.value;
	if (value.length != length) {
		alert(errorMessage);
		return false;
	}	
	return true;
}

function selectboxFilled(Field, errorMessage) {
	var value = Field.selectedIndex;
	if (value =="") {
		alert(errorMessage);
		return false;
	}
	return true;
}

function selectboxFilledNoMessage(Field) {
	var value = Field.selectedIndex;
	if (value =="") {
		return false;
	}
	return true;
}

function isValid(Field, format, errorMessage) {
	var value = Field.value;
	if (! format.test(value)) {
		alert(errorMessage);
		Field.focus();
		return false;
	}
	return true;
}

function isValidOrEmpty(Field, format, errorMessage) {
	var value = Field.value;
	if (value == "") {
		return true;
	}
	if (!format.test(value)) {
		alert(errorMessage);
		Field.focus();
		return false;
	}
	return true;
}