// isblank() - returns true if the value passed is blank or emtpy, false
//   otherwise
function isblank(value)
{
  if (value.length == 0) {
    return true;
  }
  for (i=0; i<value.length; i++) {
    if (value.charAt(i) != ' ' && value.charAt(i) != '\t' &&
        value.charAt(i) != '\n') {
      return false;
    }
  }
  return true;
}

// isNum() - returns true if the value passed is blank or numeric in
//   appearance, false otherwise.  Set negOK to true to allow for negative
//   numbers, to false to prohibit them
function isNum(value,negOK,decOK)
{
  var deccount;
  var negpos;

  if (value.length == 0) {
    return true;
  }

  negpos = value.indexOf("-");
  if (negpos != -1) {
    if (negOK == false) return false;      // No negatives allowed?
    if (negpos != 0) return false;         // Not at the beginning?
    if (value.length == 1) return false;   // - is all there is!
  }

  if (negpos == -1) i = 0;                 // Start at position 0
  else              i = 1;                 // Skip the -, start at 1

  deccount = 0;

  for ( ; i<value.length; i++) {
    if (value.charAt(i) == '.') {
      if (decOK == false) return false;    // No .'s allowed
      if (deccount == 1) return false;     // Too many points
      deccount++;
    }
    else if (value.charAt(i) < '0' || value.charAt(i) > '9') {
      return false;
    }
  }

  return true;
}

// to_dollar() - accepts a string value, assumed to be numeric
//   Converts the number into a dollar-like value
//   Examples: 5     -> 5.00
//             5.1   -> 5.10
//             5.12  -> 5.12
//             5.123 -> 5.12
//             5.789 -> 5.79
function to_dollar(amount)
{
  var strval;
  var intval;

  amount *= 100;                 // Make 5.01 = 501 or 5.2345 = 523.45
  amount = Math.round(amount);   // Round up or down
  amount /= 100;                 // Make 523 back to 5.23

  // or:
  // amount = (Math.round(amount * 100)) / 100;

  intval = parseInt(amount.toString());   // Get the integer part only
  if (intval == amount) {        // Same as number?  Need to add .00
    strval = intval + ".00";
  }
  else {
    amount = amount.toString();
    var numparts = amount.split(".");
    strval = amount;
    if (numparts[1].length == 1) strval += "0";  // Add 0 to 5.2 to make 5.20
  }

  return(strval);               // Return the amount
}

// isZip() - returns true if the value passed is a valid zip code, or
//   false if it is not.
function isZip(value)
{
  if (value.length != 5 && value.length != 10) {
    return false;
  }

  for (i=0; i<5; i++) {
    if (value.charAt(i) < '0' || value.charAt(i) > '9') {
      return false;
    }
  }

  if (value.length == 5) return true;
  if (value.charAt(5) != "-") return false;

  for (i=6; i<10; i++) {
    if (value.charAt(i) < '0' || value.charAt(i) > '9') {
      return false;
    }
  }

  return true;
}