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

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

// ----------------------------------------------------------

function isWhitespace (s){
    var i;
    // Is s empty?
    if (isEmpty(s)) 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;
}


// ------------- Some Email functions ---------------------

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 false;
    else i += 2;
    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}

// ---------

function checkEmail (theField, emptyOK)
{
	if (!isEmail(theField.value, false)){
       		// return warnInvalid (theField, iEmail);
    		return false;
    	}else{
    		return true;
    	}
}