Passing variable value in a function to be used by another function

Hello All,

I would like to ask help from you on how to pass variable value from a function that has been called inside the function. I have created below and
put the variables in " ". Is there another way I can do this? Thank you in advance.

 readtasklist() {
while read -r mod ver tarfile; do    
    case "$mod" in
     module | plugin ) ;;
    *) "unknown module: '$mod'";;
    esac
 checkversion "$mod" "$ver" "$tarfile"
done < taskfile.txt
}

What exactly is going wrong? On first (and second...) sight I can't see a problem.