效果如图
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
*{
margin:0;
padding:0;
border:0;
}
#search{
width:550px;
margin:50px auto;
}
#search input{
width:494px;
height:33px;
border:1px solid #f10215;
outline-style:none;
padding-left:4px;
color:#BBB;
font-size:14px;
font-family:"微软雅黑";
}
#search button{
width:50px;
height:35px;
color: #fff;
background-color:#f10215;
vertical-align:top;
}
</style>
<script>
var keywords = "手机";
window.onload = function(){
var txt = document.getElementById("search").getElementsByTagName("input")[0];
txt.value = keywords;
txt.onfocus = function(){
if(this.value == keywords){
this.value = "";
this.style.color = "#555"
}
}
txt.onblur = function(){
if(this.value == ""){
this.value = keywords;
this.style.color = "#BBB";
}
}
}
</script>
</head>
<body>
<div id="search">
<input type="text"><button>搜索</button>
</div>
</body>
</html>