Converting strings to titlecase in perl

There doesn't seem to be a function in perl for taking a string and returning the string in titlecase (titlecase is where the first letter of each word is capitalized).

So, I wrote one. You should be able to drop this subroutine into any perl program. You would use it like this:

$upper_string = titlecase($lower_string);

Here's the code:

sub titlecase {
#assumes lowercase, space-separated string
#returns same with first letters of words in caps

#use local variables
my ($s) = @_;
my (@st);

#split string
@st = split(/ /, $s);

#loop over strings
$n = 0;
foreach $l (@st) {
#return with first let. caps
$l = ucfirst($l);
#assign back to array
$st[$n] = $l;
$n++;
}

#join the strings into one
$s = join(" ", @st);
return $s;
}