Thanks for all your replies.

but i got a problem here-- my script is like this--

BackupLocation="$OPTARG"
                if [[ $BackupLocation != *backup ]]; then
                        echo "Appending backup subdirectories"
                        BackupLocation=$BackupLocation/backup
                        mkdir -p $BackupLocation >/dev/null 2>&1
                        if [[ $? != 0 ]];then
                        echo "First Create The Directory And Then Take backup"
                        fi
                        cd $FileLocation
                        pwd
                        cp -R $FilesToDelete $BackupLocation
                       list=$(ls *log*)
                        for files in $list
                        do
                             rm -f $files
                          touch $files.$(date +%a)
                                                 done
                else
                        mkdir -p $BackupLocation >/dev/null 2>&1
                        cp -R $FilesToDelete $BackupLocation
                        for files in $list
                        do
                          rm -f $files
                          touch $files.$(date +%a)
                          
                        done
                if [[ ! -d $BackupLocation ]]; then
                echo "Unable to make backup directory: $BackupLocation"
                        if [[ $IsCronJob -eq 1 ]]; then
                          SendMiddleTierCleanMail "Middletierclean error message" $mt_clean_errfile
                        fi