shell script : function

[will@localhost ShellScript]$ cat function.sh

#!/bin/sh
function printit(){
        echo "Your choice is $1"

}
case $1 in

  "one")

        printit 1
        ;;
  "two")
        printit 2
        ;;
  "three")
        printit 3
        ;;
  *)
        echo "Usage {one|two|three}"
        ;;

esac

[will@localhost ShellScript]$