1. 改变控件的样式表
document.getElementById("f").className = "style2";
2.改变控件的单一样式
document.getElementById("change").style.background = "black";
应用:搜索文本框
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<script type="text/javascript">
//获得焦点
function t() {
//获得当前搜索框内的内容
var txt = search.value;
//如果是初始化的内容 则清空 并设置字体黑色
if (txt == "请输入关键字……") {
search.value = "";
search.style.color = "Black";
}
}
//失去焦点
function t1() {
//获得当前搜索框内的内容
var txt = search.value;
//如果用户没有输入内容 则恢复默认值 并设置灰色
if (txt == "") {
search.value = "请输入关键字……";
search.style.color = "Gray";
}
}
</script>
</head>
<body>
<input id="search" type="text" onfocus="t()" onblur="t1()" value="请输入关键字……" style="color: Gray" />
</body>
</html>