asp函数:

<%
Const sFileExt="jpg|gif|bmp|png"
Function ReplaceRemoteUrl(sHTML, sSaveFilePath, sFileExt)
     Dim s_Content
     s_Content = sHTML
     If IsObjInstalled("Microsof" & "t.X" & "MLHTTP") = False then
         ReplaceRemoteUrl = s_Content
         Exit Function
     End If     
     Dim re, RemoteFile, RemoteFileurl,SaveFileName,SaveFileType,arrSaveFileNameS,arrSaveFileName,sSaveFilePaths
     Set re = new RegExp
     re.IgnoreCase = True
     re.Global = True
     re.Pattern = "((http|https|ftp|rtsp|mms):(\/\/|\\\\){1}((\w)+[.]){1,}(net|com|cn|org|cc|tv|[0-9]{1,3})(\S*\/)((\S)+[.]{1}(" & sFileExt & ")))"
     Set RemoteFile = re.Execute(s_Content)
     For Each RemoteFileurl in RemoteFile
arrSaveFileName = Split(RemoteFileurl,".")
  SaveFileType=arrSaveFileName(UBound(arrSaveFileName))
RanNum=Int(900*Rnd)+100
         arrSaveFileName = Year(Now()) & Right("0" & Month(Now()),2)&  Right("0" & Day(Now()),2) & Right("0" & Hour(Now()),2) & Right("0" & Minute(Now()),2) & Right("0" & Second(Now()),2) &ranNum&"."&SaveFileType
  sSaveFilePaths= sSaveFilePath
         SaveFileName = sSaveFilePaths & arrSaveFileName 
if SaveRemoteFile(""&SaveFileName&"",""&RemoteFileurl&"") then 
'response.Write ""&SaveFileName&" 图片保存成功. <br />"
s_Content = Replace(s_Content,RemoteFileurl,SaveFileName)
else 
'Response.write ""&RemoteFileurl&" 图片保存<font color='#FF0000'>失败</font>.<br />" 
end if
     Next
     ReplaceRemoteUrl = s_Content
End Function

function SaveRemoteFile(s_LocalFileName,s_RemoteFileUrl)
     Dim Ads, Retrieval, GetRemoteData
     On Error Resume Next
     Set Retrieval = Server.CreateObject("Microso" & "ft.XM" & "LHTTP")
     With Retrieval
         .Open "Get", s_RemoteFileUrl, False, "", ""
         .Send
         GetRemoteData = .ResponseBody
     End With
     Set Retrieval = Nothing
     Set Ads = Server.CreateObject("Ado" & "db.Str" & "eam") 
     With Ads
         .Type = 1
         .Open
         .Write GetRemoteData
         .SaveToFile Server.MapPath(s_LocalFileName), 2
         .Cancel()
         .Close()
     End With
     Set Ads=nothing  
if err <> 0 then 
SaveRemoteFile = false 
err.clear 
else 
SaveRemoteFile = true 
end if
End Function
Function IsObjInstalled(s_ClassString)
     On Error Resume Next
     IsObjInstalled = False
     Err = 0
     Dim xTestObj
     Set xTestObj = Server.CreateObject(s_ClassString)
     If 0 = Err Then IsObjInstalled = True
     Set xTestObj = Nothing
     Err = 0
End Function
%>

asp后台处理代码:
sSaveFileSelect=request.Form("sSaveFileSelect")
sub_content=request.form("content")
if sSaveFileSelect=1 then
Set fso=Server.CreateObject("Scripting.FileSystemObject")
yy=right(year(date),4)
mm=right("00"&month(date),2)
dd=right("00"&day(date),2)
uploaddate=yy&mm&dd
uploadpath="/editor/attached/image/"&uploaddate&"/"
If Not fso.FolderExists(Server.mappath(uploadpath)) Then
 fso.CreateFolder(Server.mappath(uploadpath))
End If
content=ReplaceRemoteUrl(sub_content,uploadpath,sFileExt)
else
content=sub_content
end if

html代码:
<input name="sSaveFileSelect" type="checkbox"  id="sSaveFileSelect" value="1"><label for="sSaveFileSelect"> 保存远程图片到本地 </label>