// whitespace characters
var whitespace = " \t\n\r";

// m is an abbreviation for "missing"

var mPrefix = "You did not enter a value into the "
var mSuffix = " This is a required field. Please enter it now."
var mCheckPrefix = "You must check the "
var mCheckSuffix = " or else you may not continue.  Please check it now."
var mDropdownPrefix = "Your choice for "
var mDropdownSuffix = " is not a valid choice.  Please choose an option."

var sName = "Name field."
var sEmail = "E-Mail Address field."
var sAddress = "Address field."
var sCity = "City field."
var sStateCode = "State field."
var sZIPCode = "ZIP Code field."
var sPhone = "Phone Number field."
var sComments = "Questions and Comments field."

var iEmail = "This field must be a valid email address (like me@myhost.com). Please reenter it now."
var iStateCode = "This field must be a valid two character U.S. state abbreviation (like DE for Delaware). Please reenter it now."
var iZIPCode = "This field must be a 5 or 9 digit U.S. ZIP Code (like 94043). Please reenter it now."
var iUSPhone = "This field must be a 10 digit U.S. phone number (like 302 555 1212). Please reenter it now."

var defaultEmptyOK = false

var USStateCodeDelimiter = "|";
var USStateCodes = "AL|AK|AS|AZ|AR|CA|CO|CT|DE|DC|FM|FL|GA|GU|HI|ID|IL|IN|IA|KS|KY|LA|ME|MH|MD|MA|MI|MN|MS|MO|MT|NE|NV|NH|NJ|NM|NY|NC|ND|MP|OH|OK|OR|PW|PA|PR|RI|SC|SD|TN|TX|UT|VT|VI|VA|WA|WV|WI|WY|AE|AA|AE|AE|AP"
var digitsInUSPhoneNumber = 10;
var ZIPCodeDelimiters = "-";
var ZIPCodeDelimeter = "-"
var validZIPCodeChars = digits + ZIPCodeDelimiters
var digitsInZIPCode1 = 5
var digitsInZIPCode2 = 9
var digits = "0123456789";

var phoneNumberDelimiters = "()- ";
var validUSPhoneChars = digits + phoneNumberDelimiters;

// Check whether string s is empty.
function isEmpty(s)
{   return ((s == null) || (s.length == 0))
}



// Returns true if string s is empty or 
// whitespace characters only.

function isWhitespace (s)

{   var i;

    // Is s empty?
    if (isEmpty(s)) return true;

    // Search through string's characters one by one
    // until we find a non-whitespace character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);

        if (whitespace.indexOf(c) == -1) return false;
    }

    // All characters are whitespace.
    return true;
}

// isEmail (STRING s [, BOOLEAN emptyOK])
// 
// Email address must be of form a@b.c -- in other words:
// * there must be at least one character before the @
// * there must be at least one character before and after the .
// * the characters @ and . are both required
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function isEmail (s)
{   if (isEmpty(s)) 
       if (isEmail.arguments.length == 1) return defaultEmptyOK;
       else return (isEmail.arguments[1] == true);
   
    // is s whitespace?
    if (isWhitespace(s)) return false;
    
    // there must be >= 1 character before @, so we
    // start looking at character position 1 
    // (i.e. second character)
    var i = 1;
    var sLength = s.length;

    // look for @
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }

    if ((i >= sLength) || (s.charAt(i) != "@")) return false;
    else i += 2;

    // look for .
    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }

    // there must be at least one character after the .
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}


// Notify user that required field theField is empty.
// String s describes expected contents of theField.value.
// Put focus in theField and return false.

function warnEmpty (theField, s)
{   theField.focus()
    alert(mPrefix + s + mSuffix)
    return false
}

function warnCheckboxEmpty (theField, s)
{   theField.focus()
    alert(mCheckPrefix + s + mCheckSuffix)
    return false
}

function warnDropdownEmpty (theField, s)
{	theField.focus()
	alert(mDropdownPrefix + s + mDropdownSuffix)
	return false
}

// Notify user that contents of field theField are invalid.
// String s describes expected contents of theField.value.
// Put select theField, pu focus in it, and return false.

function warnInvalid (theField, s)
{   theField.focus()
    theField.select()
    alert(s)
    return false
}




/* FUNCTIONS TO INTERACTIVELY CHECK VARIOUS FIELDS. */

// checkString (TEXTFIELD theField, STRING s, [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is not all whitespace.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function checkString (theField, s, emptyOK)
{   // Next line is needed on NN3 to avoid "undefined is not a number" error
    // in equality comparison below.
    if (checkString.arguments.length == 2) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (isWhitespace(theField.value)) 
       return warnEmpty (theField, s);
    else return true;
}


function checkBox (theField, s)
{
    if (!theField.checked) 
       return warnCheckboxEmpty (theField, s);
    else return true;
}

function checkDropdown (theField, s)
{
	if (theField.selectedIndex == 0)
		return warnDropdownEmpty (theField, s);
	else return true;
}
// checkEmail (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid Email.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function checkEmail (theField, emptyOK)
{   if (checkEmail.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else if (!isEmail(theField.value, false)) 
       return warnInvalid (theField, iEmail);
    else return true;
}

function AgreementcheckEmail (theField, emptyOK)
{   if (AgreementcheckEmail.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else if (!isEmail(theField.value, false)) 
       return warnInvalid (theField, iAgreementEmail);
    else return true;
}

function checkStateCode (theField, emptyOK)
{   if (checkStateCode.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    {  theField.value = theField.value.toUpperCase();
       if (!isStateCode(theField.value, false)) 
          return warnInvalid (theField, iStateCode);
       else return true;
    }
}

function isStateCode(s)
{   if (isEmpty(s)) 
       if (isStateCode.arguments.length == 1) return defaultEmptyOK;
       else return (isStateCode.arguments[1] == true);
    return ( (USStateCodes.indexOf(s) != -1) &&
             (s.indexOf(USStateCodeDelimiter) == -1) )
}

function checkZIPCode (theField, emptyOK)
{   if (checkZIPCode.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    { var normalizedZIP = stripCharsInBag(theField.value, ZIPCodeDelimiters)
      if (!isZIPCode(normalizedZIP, false)) 
         return warnInvalid (theField, iZIPCode);
      else 
      {  // if you don't want to insert a hyphen, comment next line out
         theField.value = reformatZIPCode(normalizedZIP)
         return true;
      }
    }
}

function isZIPCode (s)
{  if (isEmpty(s)) 
       if (isZIPCode.arguments.length == 1) return defaultEmptyOK;
       else return (isZIPCode.arguments[1] == true);
   return (isInteger(s) && 
            ((s.length == digitsInZIPCode1) ||
             (s.length == digitsInZIPCode2)))
}

function reformatZIPCode (ZIPString)
{   if (ZIPString.length == 5) return ZIPString;
    else return (reformat (ZIPString, "", 5, "-", 4));
}

function reformatUSPhone (USPhone)
{   return (reformat (USPhone, "(", 3, ") ", 3, "-", 4))
}

function checkUSPhone (theField, emptyOK)
{   if (checkUSPhone.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    {  var normalizedPhone = stripCharsInBag(theField.value, phoneNumberDelimiters)
       if (!isUSPhoneNumber(normalizedPhone, false)) 
          return warnInvalid (theField, iUSPhone);
       else 
       {  // if you don't want to reformat as (123) 456-789, comment next line out
          theField.value = reformatUSPhone(normalizedPhone)
          return true;
       }
    }
}

function isUSPhoneNumber (s)
{   if (isEmpty(s)) 
       if (isUSPhoneNumber.arguments.length == 1) return defaultEmptyOK;
       else return (isUSPhoneNumber.arguments[1] == true);
    return (isInteger(s) && s.length == digitsInUSPhoneNumber)
}

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;
}



// Removes all characters which do NOT appear in string bag 
// from string s.

function stripCharsNotInBag (s, bag)

{   var i;
    var 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 stripWhitespace (s)

{   return stripCharsInBag (s, whitespace)
}

function isInteger (s)
{   var i;
    if (isEmpty(s)) 
       if (isInteger.arguments.length == 1) return defaultEmptyOK;
       else return (isInteger.arguments[1] == true);
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if (!isDigit(c)) return false;
    }
    return true;
}

function isDigit (c)
{   return ((c >= "0") && (c <= "9"))
}

function reformat (s)

{   var arg;
    var sPos = 0;
    var resultString = "";

    for (var i = 1; i < reformat.arguments.length; i++) {
       arg = reformat.arguments[i];
       if (i % 2 == 1) resultString += arg;
       else {
           resultString += s.substring(sPos, sPos + arg);
           sPos += arg;
       }
    }
    return resultString;
}

function confirmEmail(firstE, secondE)
{
	if (firstE == secondE) return true;
	else
	{	alert("The e-mail addresses provided do not match.  Please confirm that the e-mail addresses are accurate.");
		return false;
	}
}
