// JavaScript Document
var DEF_WHITESPACE = " \t\n\r";
function isEmpty(input) {
        return (input.value.length == 0);
}
function containsWhitespace(input) {
    var s = input.value;
    var i;
    for(i = 0; i < s.length; i++) {
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if(DEF_WHITESPACE.indexOf(c) != -1) {
            return true;
        }
    }
    return false;
}
function isEmail(input) {
    if(isEmpty(input)) {
        return false;
    }
    // is s whitespace?
    if(containsWhitespace(input)) {
        return false;
    }

    // there must be >= 1 character before @, so we
    // start looking at character position 1
    // (i.e. second character)
    var s = input.value;
    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;
    }
}