How to handle multiple rows in a file

I have a FILE a.txt which has the following data

113901.94,113901.94,56950.97,56950.97,NOT MATCHING,NOT MATCHING
10693.04,10693.04,5346.52,5346.52,NOT MATCHING,NOT MATCHING
1901.94,1901.94,550.97,550.97,NOT MATCHING,NOT MATCHING
103.04,103.04,53.52,53.52,NOT MATCHING,NOT MATCHING

#### This IS my Code ####

RECIPIENT="xyz@mail.com"
FILE_PATH=/path/
cd $FILE_PATH
FILE=a.txt
chmod 777 $FILE

tgt_dr=`cat a.txt | awk -F',' '{print $1}' $FILE`
tgt_cr=`cat a.txt | awk -F',' '{print $2}' $FILE`

src_dr=`cat a.txt | awk -F',' '{print $3}' $FILE`
src_cr=`cat a.txt | awk -F',' '{print $4}' $FILE`

### Comparing for the Credit Amount

if [ -s $FILE ]
then

if [ $src_cr -eq $tgt_cr ]
then
exit 0
else
(echo "Hi All,

The sum of credit amount : $src_cr
The sum of credit amount : $tgt_cr

Thanks
user_name" )|mailx -s "`date '+%d-%m-%y'` Credit Amount" $RECIPIENT
fi
else
exit 0
fi

### Comparing for the Debit Amount

if [ -s $FILE ]
then
if [ $src_dr -eq $tgt_dr ]
then
exit 0
else
(echo "Hi All,

The sum of debit amount : $src_dr
The sum of debit amount : $tgt_dr

Thanks
User_name" )|mailx -s "`date '+%d-%m-%y'` Debit Amount" $RECIPIENT
fi
else
exit 0
fi

as of now my program handle only one row. pl let me know how to achieve this in looping if i have
multiple lines in the a.txt file

Thanks
Babu

This compares the whole file, writes all the credit problems to one file, all the debit problems to another, then sends all of the common problems in one email.

awk -F','   '{ if($1 != $3 ) {print $1, $3 > "debitfile"}
                  if($2 != $4 ) { print $2, $4 > "creditfile" }
                } ' a.txt
$(echo "Hi All,
`awk '{ printf( "The sum of credit amount :%10f   The sum of credit amount :%10f\n", $1, $2) creditfile`

Thanks
user_name" )|mailx -s "`date '+%d-%m-%y'` Debit Amount" $RECIPIENT
$(echo "Hi All,
`awk '{ printf( "The sum of debit amount :%10f   The sum of debit amount :%10f\n", $1, $2) debitfile`

Thanks
user_name" )|mailx -s "`date '+%d-%m-%y'` Debit Amount" $RECIPIENT

Hi

The above solutions is fine if I have only four lines. I am not sure how many lines will be created in the output a.txt.

Pl let me know how to handle in looping