AJAX异步提交

<script>
$(function(){
    $(".submit_btn").click(function(){
        if(!window.FormData){　
            alert('your brower is too old');
            return false;
        }
        var $this=$(this);
        var thisform=$this.parents('form');
        var checkform_o=true;
        $("input[required]").each(function(){
            if($.trim($(this).val())=="" && checkform_o){
                $(this).focus();
                checkform_o=false;
            }
        });
        if(!checkform_o){
            return false;
        }
        $.ajax({
            url:location.href,
            data:new FormData(thisform[0]),
            type:'post',
            cache:false,
            processData: false,
            contentType: false,
            dataType:'json',
            success:function(data){
                if(data.status==1){
                    layer.msg('修改成功', {icon: 1});
                }else{
                    layer.msg(data.msg, {icon: 2});
                }
            },
            error:function(){
                layer.msg("网络错误", {icon: 2});
            }
        });
    });
});
</script>

今天在做后台提交时,遇到AJAX提交不能够提交图***字段的数据,特别记录下。

 data:new FormData(thisform[0]),
            type:'post',
            cache:false,
            processData: false,
            contentType: false,

重点是这几行。