<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>demo01</title>
</head>
<body>
<form>
<h1>text文本框数据同步刷新</h1>
<input type="text" onpropertychange="cop()" oninput="cop1()" id="input1">
<input type="text" id="input2">
</form>
<form>
<h1>text文本框数据同步减少</h1>
<input type="text" id="input3" value="100">
<input type="text" id="input4" onpropertychange="cop()" oninput="cop2()" placeholder="减去数">
<input type="text" id="input5" placeholder="结果">
</form>
</body>
<script>
function cop1(){
var str=document.getElementById("input1").value;
b=parseInt(str);
document.getElementById("input2").value = b;
}
function cop2(){
var str=document.getElementById("input3").value;
var str1=document.getElementById("input4").value;
c=parseInt(str)-parseInt(str1);
document.getElementById("input5").value = c;
}
</script>
</html>
原文：http://www.cnblogs.com/NuLLBTF/p/6801538.html