[Bash] Checklist

Shell Programming and Scripting
1

Hello! What is the script for a checklist? This:

dialog --backtitle "Mesage" \
--title "Title" \
--checklist "Choose your favorite distribution:" 10 40 3 
         1 "RedHat" on
         2 "Ubuntu Linux" off 
         3 "Slackware" off

???
I need help!