！！a标签和button按钮只允许点击一次，防止重复提交

<button id="btn" disabled="disabled">确定</button>
2>Javascript里
<script>
    $("#btn").attr("disabled","true");
    $("#btn").attr("disabled","disabled");
    $("#btn").attr("disabled","false");
    $("#btn").removeAttr("disabled","disabled");
</script>

<a id="mybtn">button</a>
<script>
    $("a").click(function(){
        alert("1");
        $(this).css("color","#CCC");
        $(this).unbind("click");
    })
</script>

a标签 点击一次后设置点击失效，防止重复提交；

$("a").one("click",function(){

  $(this).click(function (){return false;});
});