function isValidEmail (email) {
    return (/^([a-z0-9_\-]+\.)*[a-z0-9_\-]+@([a-z0-9][a-z0-9\-]*[a-z0-9]\.)+[a-z]{2,4}$/i).test(email);
}

function textClear(id) {
    if (id.value == id.defaultValue) 
        id.value = "";
}

function textRestore(id) { 
    if (id.value == "") id.value = id.defaultValue;
}