//
// validation.js
//
// Get checked value from radio button.



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

// 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)
//
// 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
//
function isEmail (s)
{
    // 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;
}