Change filenames to uppercase (Bash)

#!/bin/bash
#CTS-1106
#7/29/14

if [ $# -ge 1 ];
then
        for item in $@
        do
                if [ -s $item ];
                then
                        echo $item | tr "a-z" "A-Z"
                else
                        echo $item is not a valid filename or is an empty file!
                fi
        done
else
        echo "You didn't enter any arguments!"
fi