防止表单重复提交

js禁用按钮：

function doSubmit(){
    $("#submitBtn").attr("disabled","disabled"); 
    $("#submitBtn").text('保存中...'); 
    var formData = $('#submitForm').serialize();
    $.ajax({
        type:'POST',
        async:true,
        timeout:10000,
        url:'/user/updateinfo',
        data:formData,
        dataType:'json',
        success:function(data){
            if(data.status==true){
                alert('保存成功'); 
            }else{
                alert(data.message);
            }
            $("#submitBtn").removeAttr("disabled"); 
            $("#submitBtn").text('保存');
            return false;
        },
        error:function(e,textStatus, errorThrown){
            $("#submitBtn").removeAttr("disabled"); 
            $("#submitBtn").text('保存'); 
            alert('发生错误，请重试');
            return false;
        }
    });
}

php session控制：

public function form(){
    $_SESSION['token'] = mt_rand(1, 9999);
}

public function submit(){
    if(empty($_POST['token']) || empty($_SESSION['token']) || $_POST['token']!=$_SESSION['token']){
        exit;
    }else{
        unset($_SESSION['token']);
    }
}

form：

<form method="post" id="submitForm" onsubmit="return doSubmit()">
    <input type="hidden" name="token" value="<?=$_SESSION['token']?>" />
    <input type="text" name="username" value="" />
    <button type="submit" id="submitBtn">保存</button>
</form>