struts 窗口问题

Question

大家帮忙看看 因为index.jsp 页面中有多个上传图片 我用打开shangchuan.jsp页面进行单独上传图片 
在shangchuan.jsp页面 提交 关闭shangchuan.jsp后 跳到java中 可是 为什么跳回来后为什么不跳到父窗口中啊
index.jsp
       <script language="javascript">
function shangchuan()
{
// var paramers="width:300px;height:200px;status:no;";   
         var paramers="dialogWidth:300px;dialogHeight:200px;status:no;";
window.showModalDialog("<%=basePath%>use/shangchuan.jsp",'',paramers); 
}
</script>
  <form action="use.do?method=tj_mima" method="post" id="form3">
  <input  type="button" onclick="shangchuan()" value="上传"/>
  </form>shangchuan.jsp
       <script type="text/javascript">
        function shangchuan()
        {
        document.getElementById("form1").submit();
        window.close();
        }
        </script>       <form style=" padding:5px;" target="_parent" action="<%=basePath %>use.do?method=up"                 method="post"        id="form1"  enctype="multipart/form-data">
       <p>请选择路径：<p>
       <p><input type="file" name="formFile" /></p>
<p style="padding-left:100px"><input type="button" value="上传" onclick="shangchuan()"/><p>
</form>server.xml
 <action path="/use" scope="request" validate="true" type="action.UseAction"  parameter="method" name="user">
    <forward name="erro" path="/erro.jsp"></forward>
    <forward name="index" path="/use/2222.jsp"></forward>
    </action> 
java 代码
   public ActionForward up(ActionMapping mapping, ActionForm form,
     HttpServletRequest request, HttpServletResponse response)
     throws Exception {
               return mapping.findForward("index");
     }