ReferenceError: completeHandler is not defined错误的解决办法。

$(':button').click(function(){
    var formData = new FormData($('form')[0]);
    $.ajax({
        url: 'upload.php',  //上传的服务器URL，upload.php内容参考下方代码
        type: 'POST',
        xhr: function() {
            var myXhr = $.ajaxSettings.xhr();
            if(myXhr.upload){
                myXhr.upload.addEventListener('progress',progressHandlingFunction, false);
            }
            return myXhr;
        },
        //Ajax 事件
        beforeSend: beforeSendHandler,
        success: completeHandler,
        error: errorHandler,
        // Form data
        data: formData,
        cache: false,
        contentType: false,
        processData: false
    });
});

当我在运行以上代码时提示： ReferenceError: completeHandler is not defined 这是因为completeHandler 是个方法我没有定义，加上就好了

function completeHandler(){
	// 这里写上上传结束后的一些代码
}