关于上传图片名称的问题 我现在用的是随机日期加图片名称 怎么改成随机日期的

<%
function makefilename()
  dim fname
  fname = now()
  fname = trim(fname)
  fname = replace(fname,"-","")
  fname = replace(fname,"/","")
  fname = replace(fname," ","")
  fname = replace(fname,":","")
  fname = replace(fname,"PM","")
  fname = replace(fname,"AM","")
  fname = replace(fname,"上午","")
  fname = replace(fname,"下午","")
  makefilename=fname
end function
%>
<%
'set tt=new upload_5xsoft
'set file=tt.file("file1")
'set file2=tt.file("file2")
set tt=new upload_5xsoft
set file1=tt.file("file1")
'if  file.FileSize>0 then         ''如果   FileSize   >   0   说明有文件数据   
'file.SaveAs   Server.mappath(bPath&file.FileName)       ''保存文件                          
'end   if                       
'set   file=nothing
%>
<%
file1.saveAs Server.mappath("../cp/"&makefilename+file1.filename)        // 关键是这里  我把+file1.filename 去掉后 上传上去的图片是随机数字但是没有图片后缀啦   就是没有.jpg   或者.gif   或者.png  没有类型啦 只是一个数字   没法打开
response.Write makefilename+file1.filename
%>
<input name="dtp" type="hidden" value="<%=makefilename+file1.filename%>" id="dtp"/>
<script>parent.document.form1.dtp.value=document.getElementById("dtp").value;</script>