function isDigit(chr){
    if ((chr < "0") || (chr > "9")) return false;
    return true;
}

function isValidPhone(phone){
    var len = phone.length;
    if (len < 10) return false;
    var digits = 0;
    for (var i = 0; i < len; i++){
        if (isDigit(phone.charAt(i))) digits++;
    }
    if (digits < 10) return false;
    return true;
}

function isValidEmail(email){
    if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(email)) return true;
    return false;
}