var defaultEmptyOK = false;

//set up basic character groups
var digits = "0123456789";
var lowercaseLetters = "abcdefghijklmnopqrstuvwxyz";
var uppercaseLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
var whitespace = " \t\n\r";
var nameDelimiters = "-. ";
var decimalPointDelimiter = ".";

//set up allowed characters for specific data types

//electronic addresses
var validDomainNameChars = digits + uppercaseLetters + lowercaseLetters + "-_.";

function makeArray(n) {
   for (var i = 1; i <= n; i++) {
      this[i] = 0;
   } 
   this[length] = n;
   return this;
}

function makeArrayFromString() {
   for (var i = 1; i <= makeArrayFromString.arguments.length; i++){
      this[i] = makeArrayFromString.arguments[i];
   }
   this[length] = makeArrayFromString.arguments.length;
   return this;
}

function isEmpty(s) {
    return ((s == null) || (s.length == 0))
}

function isWhitespace(s) {
    var i;

    if (isEmpty(s)) return true;
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if (whitespace.indexOf(c) == -1) return false; // not whitespace
    }
    return true;
}

function stripCharsInBag (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 stripCharsNotInBag (s, bag){
    var i;
    var returnString = "";
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if (bag.indexOf(c) != -1) returnString += c;
    }
    return returnString;
}

function stripWhitespace (s){
   return stripCharsInBag (s, whitespace)
}

function charInString (c, s){
    for (i = 0; i < s.length; i++){
       if (s.charAt(i) == c) return true;
    }
    return false
}

function stripInitialWhitespace (s){
    var i = 0;
    while ((i < s.length) && charInString (s.charAt(i), whitespace))
       i++;
    return s.substring (i, s.length);
}

function isLetter (c){
   return ( ((c >= "a") && (c <= "z")) || ((c >= "A") && (c <= "Z")) )
}

function isDigit (c){
   return ((c >= "0") && (c <= "9"))
}

function isLetterOrDigit (c){
   return (isLetter(c) || isDigit(c))
}

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 isSignedInteger (s){
   if (isEmpty(s)) 
       if (isSignedInteger.arguments.length == 1) return defaultEmptyOK;
       else return (isSignedInteger.arguments[1] == true);
    else {
        var startPos = 0;
        var secondArg = defaultEmptyOK;
        if (isSignedInteger.arguments.length > 1)
            secondArg = isSignedInteger.arguments[1];
        if ( (s.charAt(0) == "-") || (s.charAt(0) == "+") )
           startPos = 1;    
        return (isInteger(s.substring(startPos, s.length), secondArg))
    }
}

function isPositiveInteger (s){
    var secondArg = defaultEmptyOK;
    if (isPositiveInteger.arguments.length > 1)
        secondArg = isPositiveInteger.arguments[1];
    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) > 0) ) );
}

function isNonnegativeInteger (s){
    var secondArg = defaultEmptyOK;
    if (isNonnegativeInteger.arguments.length > 1)
        secondArg = isNonnegativeInteger.arguments[1];
    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) >= 0) ) );
}

function isNegativeInteger (s){
    var secondArg = defaultEmptyOK;
    if (isNegativeInteger.arguments.length > 1)
        secondArg = isNegativeInteger.arguments[1];
    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) < 0) ) );
}

function isNonpositiveInteger (s){
    var secondArg = defaultEmptyOK;
    if (isNonpositiveInteger.arguments.length > 1)
        secondArg = isNonpositiveInteger.arguments[1];
    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) <= 0) ) );
}

function isFloat (s){
    var i;
    var seenDecimalPoint = false;
    if (isEmpty(s)) 
       if (isFloat.arguments.length == 1) return defaultEmptyOK;
       else return (isFloat.arguments[1] == true);
    if (s == decimalPointDelimiter) return false;
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if ((c == decimalPointDelimiter) && !seenDecimalPoint) seenDecimalPoint = true;
        else if (!isDigit(c)) return false;
    }
    return true;
}

function isSignedFloat (s){
    if (isEmpty(s)) 
       if (isSignedFloat.arguments.length == 1) return defaultEmptyOK;
       else return (isSignedFloat.arguments[1] == true);
    else {
        var startPos = 0;
        var secondArg = defaultEmptyOK;
        if (isSignedFloat.arguments.length > 1)
            secondArg = isSignedFloat.arguments[1];
        if ( (s.charAt(0) == "-") || (s.charAt(0) == "+") )
           startPos = 1;    
        return (isFloat(s.substring(startPos, s.length), secondArg))
    }
}

function isAlphabetic (s){
    var i;
    if (isEmpty(s)) 
       if (isAlphabetic.arguments.length == 1) return defaultEmptyOK;
       else return (isAlphabetic.arguments[1] == true);
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if (!isLetter(c))
        return false;
    }
    return true;
}

function isAlphanumeric (s){
    var i;
    if (isEmpty(s)) 
       if (isAlphanumeric.arguments.length == 1) return defaultEmptyOK;
       else return (isAlphanumeric.arguments[1] == true);
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if (! (isLetter(c) || isDigit(c) ) )
        return false;
    }
    return true;
}

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 isEmail (s){
    if (isEmpty(s)) {
       if (isEmail.arguments.length == 1) return defaultEmptyOK;
       else return (isEmail.arguments[1] == true); }
    if (isWhitespace(s)) return false;
    var i = 1;
    var sLength = s.length;
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++ }
    if ((i >= sLength) || (s.charAt(i) != "@")) return ("no @ sign");
    else atloc = i;
    j = i+1;
    i += 1;
    while ((j < sLength) && (validDomainNameChars.indexOf(s.charAt(j)) != -1))
    { j++ }
    if (j < sLength) return("invalid character in domain name: "+s.charAt(j));
    while ((i < sLength) && (s.charAt(i) != "."))
    { i++ }
    if (i == sLength) return("no . in domain name");
    if (i == (atloc +1)) return("not enough space between @ and .");
    k = atloc+1;
    while (k < sLength){
      if ((s.charAt(k) == ".") && (s.charAt(k+1) == ".")) return("too many .'s");
      k++
    }
    l = sLength;
    while ((i < sLength -2) && (l != i) && (s.charAt(l) != "."))
    { l = l-1 }
    if ((i >= sLength - 2) || (s.charAt(i) != ".") || (l >= sLength - 2)) return("not enough chars after .");
    else return true;
}

function prompt (s){
    window.status = s
}

function warnInvalid (theField,s){
//    theField.focus()
    theField.select()
    alert(s)
    return false
}

function checkEmail (theField, emptyOK){
    if (checkEmail.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else {
      emailStatus = isEmail(theField.value, false)
      if (emailStatus != true) return warnInvalid (theField, "Invalid Email Address");
      else return true;
    }
}