Linux shell script to monitor changed files

Hi,

I am trying to write a shell script to monitor file changes in Red hat linux but had some problems.

=============filemod.sh=========================

#!/bin/bash

dir=/
freq='-1'
email=me@domain.com
udate=`date +%y-%m-%d`
utime=`date +%H:%M`
check=`find $dir -mtime $freq -type f -exec ls -lh {} \;`
count=`cat $check | wc -l`

if [ $count -gt 0 ]
then
               sub="Attention! $count File Modified on $udate at $utime"
              echo `cat $check` | mail -s "$sub" $email
        else
               echo "no files were modified on $udate at $utime
       fi

fi

I have problems to execute the script. Can someone please optimize it or correct it. I need this report should email on dialy basis for every day (so may be -1 should ok?) and also use cron for this

thanks