SELECT在浏览器中相关Bug整理

//判断是否是IE7以下浏览器
if (navigator.appVersion.indexOf("MSIE 5.5") >= 0 || navigator.appVersion.indexOf("MSIE 6.0") >= 0
|| navigator.appVersion.indexOf("MSIE 7.0") >= 0) {
window.attachEvent("onload", function() {
ReloadSelectElement();
//给所有select添加事件
function ReloadSelectElement() {
var s = document.getElementsByTagName("select");
if (s.length > 0) {
for (var i = 0, select; select = s[i]; i++) {
(function(e) {
//获得焦点时，将当前选中的项目记录下来
e.attachEvent("onfocus", function() {
e.setAttribute("current", e.selectedIndex);
});
//项目改变时，如果选中的是“无效”的项目，则返回返回前一状态
e.attachEvent("onchange", function() {
restore(e);
});
})(select)
//将含有disabled属性的项目“无效化”
emulate(select);
}
}
}
function restore(e) {
if (e.options[e.selectedIndex].disabled) {
e.selectedIndex = e.getAttribute("current");
}
}
function emulate(e) {
for (var i = 0, option; option = e.options[i]; i++) {
if (option.disabled) {
option.style.color = "graytext";
}
else {
option.style.color = "menutext";
}
}
}
})
}

<select id="s" style="width:100px;background:lightskyblue"></select>
<select id="s2" style="width:100px;background:lightgrey"></select>
<script>
var s = document.getElementById("s");

//方式1
s.add(new Option("A", 1));
//方式2
s.appendChild(new Option("B", 2));
//方式3
s.insertBefore(new Option("C", 3),s.options[2]);
//方式4
s.options[3] = new Option("D", "B");
//方式5
var op = document.createElement("option");
op.appendChild(document.createTextNode("E"));
s.appendChild(op);
//方式6
var s2 = document.getElementById("s2");
s2.innerHTML = "<option>X</option><option>Y</option>";
</script>