// JavaScript Document
var defaultEmptyOK = false
var whitespace = " \t\n\r";
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 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 checkform (form) {
    if (isEmail(form.email.value)) { 
        return true;
    } else {
        alert("You must enter a valid e-mail address");
        return false;
    }
}