Macro not saving file in excel format

Hello,


I have a coding like this:

filename = Range("B3").Value
Workbooks.Add
    Set newwb = ActiveWorkbook
    ChDir "D:\P3\Jan-11\B2B"
    ActiveWorkbook.SaveAs filename, FileFormat _
        :=xlExcel8, Password:="", WriteResPassword:="", ReadOnlyRecommended:= _
        False, CreateBackup:=False

I am using excel2007 but I have to save file in excel2003.

by this command the file is saved with said name but the file type is not excel, the type just come as "file". on the contrary some files are saving in excel format when I excute the code again and again.

kindly help me whats wrong in the code.

Thanks!
Rahul