判断表单是否提交
<%
//这样是取不到已经提交的表单值的，有其他办法判断改表单是否提交嘛？？
String post=request.getParameter( "post ");
System.out.println( "post= "+post);
if ((post!=null)&&post.equals( "1 ")) {
...
}
%>
<form name= "PostForm " method= "post " enctype= "multipart/form-data " action= " ">
<input name= "post " type= "hidden " value= "1 ">
<input name= "attach " type= "submit " value= "发送 " >
</form>
[解决办法]
给form的action增加一个参数，比如isPost＝1，下次就判断isPost是不是1就完了
