Is CUT the right command?

Attempting to pass in-line parameters & values to a shell script, using the CUT command to split a value where a ',' delimiter is used. The format of the passed value will be '00:00:00,00:00:00'.
If I create a file with the contents "12:34:56,12:34:56", using the command
cut -d, -f1 < file
I get back 12:34:56 - so far so good.

However, the script below doesn't work (I've 'echoed' ${OPTARG} and the value is getting into the script OK):

#!/bin/sh

while getopts m: opt
do
case ${opt} in
m) val1=`${OPTARG} | cut -d, -f1`
val2=`${OPTARG} | cut -d, -f2`;;
*) helpmenu;;
esac
done

Can anyone please give me any pointers why not? Total newbie to this so I may well be missing the obvious........

Kutz13,
The command 'getopts' is used to process command line arguments
using the '-' (dash) format.

It is not required in your specific situation.

Try the following:

mVal1=`echo $1 | cut -d, -f1`
mVal2=`echo $1 | cut -d, -f2`

Sorry, maybe my terminology was wrong. What I intended to show were the arguments associated with the command line option '-m'. So that when <filename> -m 123:456,654:321 was entered I could extract into $val1 & $val2 the respective values 123:456 & 654:321.

You are missing an echo as illustrated by Shell's code. Try

    m) val1=`echo ${OPTARG} | cut -d, -f1`
       val2=`echo ${OPTARG} | cut -d, -f2`;;

That's great, issue solved.