// scripped down version of:
// http://developer.netscape.com/docs/examples/javascript/formval/FormChek.js

var digits = "0123456789";

var whitespace = " \t\n\r";

var decimalPointDelimiter = "."

var defaultEmptyOK = false



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


    return true;
}


function stripCharsInBag (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 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) ) );
}