Shell Programming and Scripting

Hi
I have many file initial size zero(empty) after some munipulation , one or more file will be greater than zero. I need to send those file names if they return to zero again.
Ex.
Initially the files are zero size

Code:

Size  filename
 0         AAA
 0         BBB
 0         CCC
 0        DDD

Then
With some munipulation the files could be like below

Code:

Size  filename
 20       AAA
 0         BBB
 30       CCC
 0        DDD

If AAA and CCC become zero again then i need to email the file name

Appreciate ur assist

My shell script is working fine till the file size change but i could determine those file when get back to zero size.
I need help to just distingush file has size change to zero as all my files will have zero @ the end.