【JS练习】记住密码提示框

参考：http://www.fgm.cc/learn/lesson1/06.html

        <script type="text/javascript">

        window.onload = function() {
            var oLab = document.getElementsByTagName("label")[0];
            var oTip = document.getElementById("remainder");
            oLab.onmouseover = function() {
                oTip.style.display = "block"
            };
            oLab.onmouseout = function() {
                oTip.style.display = "none"
            }
        }
        </script>