// Check that the number of characters in a string is between a max and a min
function isValidLength(string, min, max) {
	if (string.length < min || string.length > max) return false;
	else return true;
}


// Check that an email address is valid
function isValidEmail(address) {
	address = trimWhitespace(address)
	if (!isValidLength(address, 7, 255))
		return false;
	if (address != '' && address.search) {
      if (address.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1) return true;
      else return false;
	}
	
   else return true;
}

// Check that a US zip code is valid
function isValidZipcode(zipcode) {
	zipcode = removeSpaces(zipcode);
	if (!(zipcode.length == 5 || zipcode.length == 9 || zipcode.length == 10)) return false;
   if ((zipcode.length == 5 || zipcode.length == 9) && !isNumeric(zipcode)) return false;
   if (zipcode.length == 10 && zipcode.search && zipcode.search(/^\d{5}-\d{4}$/) == -1) return false;
   return true;
}

// Check that a US or Canadian phone number is valid
function isValidUSPhoneNumber(areaCode, prefixNumber, suffixNumber) {
   if (arguments.length == 1) {
      var phoneNumber = arguments[0];
      phoneNumber = phoneNumber.replace(/\D+/g, '');
      var length = phoneNumber.length;
      if (phoneNumber.length >= 7) {
         var areaCode = phoneNumber.substring(0, length-7);
         var prefixNumber = phoneNumber.substring(length-7, length-4);
         var suffixNumber = phoneNumber.substring(length-4);
      }
      else return false;
   }
   else if (arguments.length == 3) {
      var areaCode = arguments[0];
      var prefixNumber = arguments[1];
      var suffixNumber = arguments[2];
   }
   else return true;

   if (areaCode.length != 3 || !isNumeric(areaCode) || prefixNumber.length != 3 || !isNumeric(prefixNumber) || suffixNumber.length != 4 || !isNumeric(suffixNumber)) return false;
   return true;
}

// Check that a string contains only letters and numbers
function isAlphanumeric(string, ignoreWhiteSpace) {
	if (string.search) {
		if ((ignoreWhiteSpace && string.search(/[^\w\s]/) != -1) || (!ignoreWhiteSpace && string.search(/\W/) != -1)) return false;
	}
	return true;
}

// Check that a string contains only letters
function isAlphabetic(string, ignoreWhiteSpace) {
	if (string.search) {
		if ((ignoreWhiteSpace && string.search(/[^a-zA-Z\s]/) != -1) || (!ignoreWhiteSpace && string.search(/[^a-zA-Z]/) != -1)) return false;
	}
	return true;
}

// Check that a string contains only numbers
function isNumeric(string, ignoreWhiteSpace) {
	if (string.search) {
		if ((ignoreWhiteSpace && string.search(/[^\d\s]/) != -1) || (!ignoreWhiteSpace && string.search(/\D/) != -1)) return false;
	}
	return true;
}

// Remove characters that might cause security problems from a string 
function removeBadCharacters(string) {
	if (string.replace) {
		string.replace(/[<>\"\'%;\)\(&\+]/, '');
	}
	return string;
}

// Remove all spaces from a string
function removeSpaces(string) {
	var newString = '';
	for (var i = 0; i < string.length; i++) {
		if (string.charAt(i) != ' ') newString += string.charAt(i);
	}
	return newString;
}

// Remove leading and trailing whitespace from a string
function trimWhitespace(string) {
	string = string+"";
	var newString  = '';
	var substring  = '';
	beginningFound = false;

	// copy characters over to a new string
	// retain whitespace characters if they are between other characters
	for (var i = 0; i < string.length; i++) {
		
		// copy non-whitespace characters
		if (string.charAt(i) != ' ' && string.charCodeAt(i) != 9) {
			
			// if the temporary string contains some whitespace characters, copy them first
			if (substring != '') {
				newString += substring;
				substring = '';
			}
			newString += string.charAt(i);
			if (beginningFound == false) beginningFound = true;
		}
		
		// hold whitespace characters in a temporary string if they follow a non-whitespace character
		else if (beginningFound == true) substring += string.charAt(i);
	}
	return newString;
}

function Date_Validate(mm,dd,yyyy)
{
   var chk    = 0;
   var maxDay = 0;

// calling function to get maximum day for this month
maxDay = max_day(mm, yyyy);  

if((dd <= 0) || (dd > maxDay))
{ chk = 1;}
else if((mm <= 0) || (mm > 12))
{ chk = 1;}
else if((yyyy <= 0))
{ chk = 1;} 

if(chk == 1)
	return false;
else
	return true;
}
// function for calculating maximum day 
function max_day(mn, yr)
{
   var mDay;
if((mn == 4) || (mn == 6) || (mn == 9) || (mn == 11))
{ 
mDay = 30;
}
else if(mn == 2)
{
//calling leap year function 
mDay = isLeapYear(yr) ? 29 : 28;    
}
else
{
mDay = 31;
}
return mDay; 
}

    // function to check leap year
function isLeapYear(yr)
{
if (yr % 2 == 0) 
   return true;
   return false;
}

function isAmount(f)
{
	var isFloat = parseFloat(f)
	var isFloatStr = isFloat+"";
	if(isFloat == 0 || isFloatStr == "NaN")
		return false
	else
		return true
}

function isCreditCard(st) {
  // Encoding only works on cards with less than 19 digits
  
  if(removeSpaces(st).length == 0)
  	return (false);
  
  if (st.length > 19)
    return (false);

  sum = 0; mul = 1; l = st.length;
  for (i = 0; i < l; i++) {
    digit = st.substring(l-i-1,l-i);
    tproduct = parseInt(digit ,10)*mul;
    if (tproduct >= 10)
      sum += (tproduct % 10) + 1;
    else
      sum += tproduct;
    if (mul == 1)
      mul++;
    else
      mul--;
  }
// Uncomment the following line to help create credit card numbers
// 1. Create a dummy number with a 0 as the last digit
// 2. Examine the sum written out
// 3. Replace the last digit with the difference between the sum and
//    the next multiple of 10.

//  document.writeln("<BR>Sum      = ",sum,"<BR>");
//  alert("Sum      = " + sum);

  if ((sum % 10) == 0)
    return (true);
  else
    return (false);

}

function isVisa(cc)
{
  if (((cc.length == 16) || (cc.length == 13)) &&
      (cc.substring(0,1) == 4))
    return isCreditCard(cc);
  return false;
} 

function isMasterCard(cc)
{
  firstdig = cc.substring(0,1);
  seconddig = cc.substring(1,2);
  if ((cc.length == 16) && (firstdig == 5) &&
      ((seconddig >= 1) && (seconddig <= 5)))
    return isCreditCard(cc);
  return false;

}

function isAmericanExpress(cc)
{
  firstdig = cc.substring(0,1);
  seconddig = cc.substring(1,2);
  if ((cc.length == 15) && (firstdig == 3) &&
      ((seconddig == 4) || (seconddig == 7)))
    return isCreditCard(cc);
  return false;

}

function isDiscover(cc)
{
  first4digs = cc.substring(0,4);
  if ((cc.length == 16) && (first4digs == "6011"))
    return isCreditCard(cc);
  return false;

}

function isDinersClub(cc)
{
  firstdig = cc.substring(0,1);
  seconddig = cc.substring(1,2);
  if ((cc.length == 14) && (firstdig == 3) &&
      ((seconddig == 0) || (seconddig == 6) || (seconddig == 8)))
    return isCreditCard(cc);
  return false;
}

function CountWords(text)
{
var char_count = text.length;
var fullStr = text + " ";
var initial_whitespace_rExp = /^[^A-Za-z0-9]+/gi;
var left_trimmedStr = fullStr.replace(initial_whitespace_rExp, "");
var non_alphanumerics_rExp = rExp = /[^A-Za-z0-9]+/gi;
var cleanedStr = left_trimmedStr.replace(non_alphanumerics_rExp, " ");
var splitString = cleanedStr.split(" ");
var word_count = splitString.length -1;
if (fullStr.length <2) {
word_count = 0;
}
if (word_count == 1) {
wordOrWords = " word";
}
else {
wordOrWords = " words";
}
if (char_count == 1) {
charOrChars = " character";
} else {
charOrChars = " characters";
}
return word_count;

}

function isValidMessage(text)
{
	var count = CountWords(text);
	if(count > 100)
		return false;
	else
		return true;
}

function isValidFile(str){
  var re = /[^\d\sa-zA-Z0-9\(\)\<\>\:\\\/\_\.]/g
  if (re.test(str)) return false;
  return true;
}

function isRequired(value) {
	value = removeSpaces(value);
 	if (value.length == 0) return false;
	return true;
}