writeable fies can't be deleted

[charon]

I don't why, the delete file's function work fine until now, it has problem on deleting the files which have been set to writeable....Permission Denied,

Sub RemoveTempImages(strFolder, strPrefix, ExpireDate)
Dim Fso, FolderInfo, FileList, nPrefixLen

nPrefixLen = Len(strPrefix)
Set Fso = Server.CreateObject("Scripting.FileSystemObject")

Set FolderInfo = Fso.GetFolder(strFolder)
Set FileList = FolderInfo.Files

For Each File in FileList
if LCase(Left(File.Name, nPrefixLen)) = LCase(strPrefix) AND _
File.DateCreated < ExpireDate then
Fso.DeleteFile File.Path 'even i try to set to true also cannot
end if
Next

Set FileList = Nothing
Set FolderInfo = Nothing
Set Fso = Nothing

End Sub


Please help!