Mount Monitor Basic shell script

#!/bin/ksh
#
SID=$1
Mount="$SID/dbdata/data"
FLAG='N'
for M in `df -k | grep $Mount |awk '{print $5":"$6}'`; do
   PCT=`echo $M | awk -F\: '{print $1}' | awk -F\% '{print$1}'`
echo "PCT is " $PCT
   MNT=`echo $M | awk -F\: '{print $2}'`
echo "MNT is " $MNT
   if [[ $PCT -lt 85 ]]; then
    echo "Space is ok"
    FLAG='Y'
    exit 0
   fi
done
if [[ $FLAG = "N" ]]; then
   echo "space low, put in request"
else
   echo "Something wrong"
fi