如果<button>标签在<form>中不加type=“button”，那么默认含义是“submit”。
<button>标签里面disabled属性使其不可用，常见javascript修改disabled属性实例：（a键b键互相撕逼）
<style>
#a,#b
{
height:30px;
70px;
background:yellow;
box-sizing:border-box；
}
</style>
</head>
<body>
<button type="button" id="a" onclick="an()" >会变色</button>
<button type="button" id="b" onclick="bn()" >会变色</button>
<script>
function bn()
{
if(document.getElementById("b").disabled!="true")
{
document.getElementById("b").disabled="true";
document.getElementById("b").style.background="gray";
document.getElementById("a").removeAttribute("disabled");
document.getElementById("a").removeAttribute("style");
}
else
{
document.getElementById("a").disabled="true";
document.getElementById("a").style.background="gray";
document.getElementById("b").removeAttribute("disabled");
document.getElementById("b").removeAttribute("style");
}
}
function an()
{
if(document.getElementById("a").disabled!="true")
{
document.getElementById("a").disabled="true";
document.getElementById("a").style.background="gray";
document.getElementById("b").removeAttribute("disabled");
document.getElementById("b").removeAttribute("style");
}
else
{
document.getElementById("b").disabled="true";
document.getElementById("b").style.background="gray";
document.getElementById("a").removeAttribute("disabled");
document.getElementById("a").removeAttribute("style");
}
}
</script>
</body>