Program in UNIX to find out at how many terminals has this user logged in

While executing a shell script either the LOGNAME or the UID is supplied at the command prompt. Write a shell script to find out at how many terminals has this user logged in.

echo "Enter the LOGNAME"
read lgname
x=`who | grep $lgname | wc -l`
if [ $x -eq 0 ]
then
echo "user name did not logged"
fi
echo "Number of terminal $lgname has logged in is $x"