Problem with Getoptions (please help)

I have the script below. But when I insert the variables url and nameorg to execute it, I received the following error message: Scheme missing.

#!/usr/bin/perl

use strict;
use warnings;
use diagnostics;
use Getopt::Long;

my $url= '';

print "&&&&$url&&&&"."\n";

my $nameorg= '';

#my $nameorg= "Staphylococcus_aureus_04_02981_uid161969"; #organismo que buscamos

print "%%%%$nameorg%%%%"."\n";

#LA OPCION DE GetOptions funciona, pero sale un error que es

if(!$url){
warn "no ha puesto url\n";
&usage();
}

elsif (!$nameorg) {
warn "no ha puesto el nombre del organismo";
&usage();
}

sub usage {
print 'tutorial script';
}

GetOptions('url' => \$url, 'nameorg' => \$nameorg);

###############################################

my $cmd_wget="wget $url".$nameorg."/*.fna\n";

system($cmd_wget);

#################################################


I don't know what to do. Can somebody help me?