#!/bin/bash

err_fn()
{
echo here is my error function
echo $1
echo and $2
}

echo please enter a 1 or a 2
read number

#note that the function has 2 arguments PASSED to it
#those arguments are totally seperate from the command line
#arguments even though it has the same familiar name '$1 and $2' as
#the command line arguments
if [ $number -eq 1 ]
	then 
		err_fn "You entered a 1" "this is the second err_fn argument"
	else
		err_fn "you entered a 2" "$1"
fi

echo the argument '$1' that you entered at the command line is $1
echo it is totally seperate from the argument '$1' 
echo that you passed to the function