怎么用javascript去验证焦点

Question

有哪位高手知道怎么用javascript去验证焦点

Answer 1

if(document.activeElement.id == "objectID")                                           

Answer 2

    <script type="text/javascript">
    function chfocus()
    {
    if(!document.getElementById("txtName").focus())
    {
    alert("当前焦点不在姓名上");
    document.getElementById("txtName").select();
    return false;
    }
    return true;
    }
    </script>