<dsp:form action="${originatingRequest.requestURI}" method="post" enctype="multipart/form-data">
  <dsp:input type="file" bean="ReturngoodsFormHandler.uploadedFile1" id="uploadedFile1" value="" onchange="checkfile('uploadedFile1');"/>
  <dsp:input type="file" bean="ReturngoodsFormHandler.uploadedFile2" id="uploadedFile2" value="" onchange="checkfile('uploadedFile2');"/>
  <a class="btn_sprite btn_font14_red" href="javascript:;" rel="external nofollow" ><span>提交申请</span></a>

   <dsp:input type="submit" style="display:none;" bean="ReturngoodsFormHandler.submitReturngoods" id="submitReturngoods" value="Add"/>

   </dsp:form>

//将验证的设置和错误信息抽离出来，有利于最后submit时候做判断

var flag=true;
 var errorinfo="";

//验证文件的格式
 function checkfile(filenames){
  filename=document.getElementByIdx_x_x(filenames).value;

  var re=/(.[.]bmp)$|(.[.]gif)$|(.[.]jpg)$|(.[.]png)$|(.[.]jpeg)$/i;
  if (!re.test(filename)) {
  errorinfo = "只支持bmp,gif,jpg,png,jpeg格式文件，请重新上传";
  alert(errorinfo);
  flag = false;
  return false;
   }

//验证文件的大小
   if(document.getElementByIdx_x_x(filenames).size>8000){
   errorinfo = "文件必须小于800KB,图片太大 size:"+document.getElementByIdx_x_x_x_x_x(filenames).size;
   alert(errorinfo);
   return false;
   }
 }

 jQuery('.btn_font14_red').click(function(){
 if(flag==true){
  $("#submitReturngoods").click();
 }else{
  alert(errorinfo);
  return false;
 } 

 });