<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<style type="text/css">
*{
margin: 0;
padding: 0;
}
.box{
width: 400px;
height: 200px;
margin: 100px auto;
border: solid 1px grey;
}
input{
width:200px;
height: 50px;
margin-left: 20px;
margin-top: 75px;
color: #ccc;
}
button{
width: 50px;
height: 50px;
margin-left: 20px;
}
</style>
<script type="text/javascript">
window.onload = function(){
function $(id){
return document.getElementById(id);
}
$(‘txt‘).onfocus = function(){
if(txt.value==‘请输入您的号码进行过查询‘){
txt.value = ‘‘;
txt.style.color = ‘#333‘;
}
}
txt.onblur = function(){
if(txt.value==‘‘){
txt.value = ‘请输入您的号码进行过查询‘;
txt.style.color = ‘#ccc‘;
}
}
var attr = [10066];
$(‘btn‘).onclick = function(){
for(var i=0;i<attr.length;i++){
if($(‘txt‘).value==attr[i])
{
alert(‘恭喜，您中奖了‘);
}
else{
alert(‘抱歉，欢迎下次再来‘);
}
}
}
}
</script>
</head>
<body>
<div class="box">
<input type="text" value="请输入您的号码进行过查询" id="txt" />
<button id="btn">查询</button>
</div>
</body>
</html>
效果相当于css中的peacholder
原文地址：https://www.cnblogs.com/verayangnakiss/p/8455687.html