<%
String path = request.getContextPath()
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/"
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>JS修改背景</title>
<script type="text/javascript">
function JS() {
document.addmemeber("form1").memberName("int1").style.background = '#eeeeee'
}
function hid(){
var value = document.getElementByIdx_x("h").value
alert(value)
}
</script>
</head>
<body>
<form action="" name="form1">
<input type="text" name="int1" value="" onclick="JS()"/><br/>
<input type="hidden" id="h" name="h" value="隐藏"/>
<input type="button" value="按钮" onclick="hid()"/>
</form>
</body>
</html>
默认的边框样式应该是无法恢复的，不同浏览器的边框也不一样。
不过你可以在文本框外面加一个span，只改变span的边框（需要调整一下padding），这样就可以恢复了：
<html><head>
<script type="text/javascript">
var t = 0
function showBorder() {
var answer3 = document.getElementById("yearId").value
if (t == 0) {
t = 1
document.getElementById("yearId").parentElement.style.border = "0"
}
else {
t = 0
document.getElementById("yearId").parentElement.style.border = "1px solid black"
}
}
</script>
</head>
<body>
<span style="padding-bottom: 2px padding-top: 1px padding-left: 0 padding-right: 0">
<input type="text" id="yearId" name="yearId" size="16" /></span>
<input type="button" value="show border" onclick="showBorder()" />
</body>
</html>
效果图：
