Email message if file size > 0 bytes

I want to create a script that emails a file created by Informix Ace if the file size is > 0. It is a list of exceptions. No exceptions...no message

This does not work:

THESIZE=`ls -lA /tmp/ds_treo.txt | awk -F' ' '{print $5}'`

if [ $THESIZE=0 ]
then
(cat $DSDIR/ds_treo.txt) | mail -s "Treo Daily Sales Report FS" jsayre@bebe.com
fi

What would?

I am a novice with this stuff...

if [[ $(cksum /tmp/ds_treo.txt | nawk '{print $2}') -gt 0 ]]
then
    your mail command
fi