var whitespace = " \t\n\r";
var digits = "0123456789";

function isEmpty(s)
{   return ((s == null) || (s.length == 0))
}
function isDigit (c)
{   return ((c >= "0") && (c <= "9"))
}
function isWhitespace (p)
{   var i;
	var s=p.value;
    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 isInteger (p)
{   var i;
	var s=p.value;
    if (isEmpty(s)) return false;
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if (!isDigit(c)) return false;
    }
    return true;
}
function isOption(s)
{   return (s.selectedIndex > 0)
}
function isEmail (p)
{   var s=p.value;
	if (isEmpty(s)) return false;
    if (isWhitespace(p)) return false;
    var i = 1;
    var sLength = s.length;
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }
    if ((i >= sLength) || (s.charAt(i) != "@")) return false;
    else i += 2;
    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}
function isURL (p)
{	var s=p.value;
	if (isEmpty(s)) return false;
	if (isWhitespace(p)) return false;
	var re = /^http:\/\/.+\..+/;
	return re.test (s);
}