[lord2kim]

chaynic,

<script>
function func() {
    if (document.getElementById("name").checked) {
        document.getElementById("lastname").disabled = true;
        document.getElementById("lastname").checked = false;
    }
    else {
        document.getElementById("lastname").disabled = false;
    }
}
</script>
<input type="checkbox" id="name" onClick = "func()">1
<input type="checkbox" id="lastname">2