This should solve your problem :

#!/usr/local/bin/perl

use strict;

$myname=myname();
print "my name is $myname\n";

sub myname {
    my $myname = "bill";
    return $myname;
}
[download]

Your problem is that you seem to not understand the scope of variable (the way my works)
and the way a sub return the value (you call a sub returning the value needed in a void context)
I would have (re)written it this way :

#!/usr/local/bin/perl

use strict;

my $name=myname();
print "my name is $name\n";

sub myname {
    my $myname = "bill";
    return $myname;
}
[download]

Now you should see that the var in the sub has nothing to do with the one outsite the sub
(it's a lexically scoped var, which doesn't exist anymore outside the scope of the sub)

"Only Bad Coders Badly Code In Perl" (OBC2IP)