return value problem

hi ,
Consider the following code
#!/bin/sh

# addagenda

isMonthName()
{
case $(echo $1 | tr '[[:upper:]]' '[[:lower:]]') in
jan*|feb*|mar*|apr*|may*|jun*) return 0 ;;
jul*|aug*|sep*|oct*|nov*|dec*) return 0 ;;
*) return 1 ;;
esac
}

echo -n "Enter Day of event "
read word1

x=isDayName $word1
echo $x

In the above script when i print the value of x ,Null value is getting printed.(It should print 0 or 1)

any help pls.
Cheers
RRK

try the following

isDayName $word1 
x=$?
echo $x

hi poter,
Thanks a lot.
It worked.
cheers
RRK

isDayName $word1  >/dev/null  # If you don't want the output of this command to be displayed on the console
x=$?
echo $x