Making a shell script...

[Xpression]

Hi guys:
            I try to make a script to rotate some log files every month,
file must be appear like this   (Month-Year.tgz)...the question is: how can
I compress all files in a sub-dir that contains many sub-dirs without
compress sub-dirs too...sample:

/mydir/one-dir
          /another-one
          file1
          file2
          file3

I try to tar & compress file[1..3] without compress /one-dir, /another-one
directories...I'm already looked at man pages without a response...thanks