如何停止文件上传在特定的javascript事件在上传 - How to stop file upload at specific javascript event in uploadify

How to stop file upload at specific javascript event in uploadify

我有下面的代码。上传工作正常。现在，当我不输入视频标题并选择视频文件上传时，它会给我javascript消息来输入视频标题，但之后立即通过uploadify开始视频上传。所以如果没有选择视频标题，我想停止视频上传过程。请帮忙解决这个问题。

function frm_add_validateform()
{
    with(document.frm_add)
    {
        if(trim(txt_title.value)=="")
        {
            alert("Please enter video clip title.");
            txt_title.focus();
            return false;
        }
    }
    return true;
}
<form name="frm_add" action="video_clip_add_p.php?pkid=<?php print($int_pkid);?>" method="post" onSubmit="return frm_add_validateform();" enctype="multipart/form-data">
<input type="text" id="txt_title" name="txt_title" class="clsTextBox" size="100" maxlength="100">
<input type="file" id="file_upload" name="file_upload" placeholder="Select your file to upload">

试试这个:

 function frm_add_validateform()
    {
        with(document.frm_add)
        {
            if(trim(txt_title.value)=="")
            {
                alert("Please enter video clip title.");
                txt_title.focus();
                $('#file_upload').uploadify('stop'); //stop video upload
                return false;
            }
        }
        return true;
    }