<s:form action="upload.action" theme="simple" method="post" enctype="multipart/form-data">
<table align="center" width="50%" border="1">
<tr>
<td>
上传文件
</td>
<td id="more" >
<s:file name="upload" id="file" onblur="subalert()"></s:file>
<input type="button" value="上传更多..." onclick="addMore()">
</td>
</tr>
<tr>
<td>
<s:submit value=" 确认 "></s:submit>
</td>
<td>
<s:reset value=" 重置 "></s:reset>
</td>
</tr>
</table>
</s:form>
<table align="center" width="50%" border="1">
<tr>
<td>
上传文件
</td>
<td id="more" >
<s:file name="upload" id="file" onblur="subalert()"></s:file>
<input type="button" value="上传更多..." onclick="addMore()">
</td>
</tr>
<tr>
<td>
<s:submit value=" 确认 "></s:submit>
</td>
<td>
<s:reset value=" 重置 "></s:reset>
</td>
</tr>
</table>
</s:form>
换为<s:button value=" 确认 " onclick="submit();"></s:button>function submit(){
if (document.getElementById('file') == '') return false;
else document.forms[0].submit();
}