Perl class help

Shell Programming and Scripting
1

cat a.pl

#!/usr/bin/perl

package Myperlclass;
sub mysub{
    my $class;
    $class=shift;
    my $self{};
    bless $self,$class;
    return $self;
}
sub add{
    my $a,$b,$res;
    $a=$_[0];
    $b=$_[1];
    $res=$a+$b;
    print "res: $res\n";
}

cat b.pl

#!/usr/bin/perl

use Myperlclass;
$obj=new Myperlclass();
$obj->add(4,5);

perl b.pl
Error:

Can't locate Myperlclass.pm in @INC (@INC contains: 
/usr/lib/perl5/5.10.0/i586-linux-thread-multi 
/usr/lib/perl5/5.10.0 /usr/lib/perl5/site_perl/5.10.0/i586-linux-thread-multi 
/usr/lib/perl5/site_perl/5.10.0 
/usr/lib/perl5/vendor_perl/5.10.0/i586-linux-thread-multi 
/usr/lib/perl5/vendor_perl/5.10.0 /usr/lib/perl5/vendor_perl .)
 at call_perl.pl line 3.
BEGIN failed--compilation aborted at call_perl.pl line 3.

Can i call class member function in same a.pl file?

---------- Post updated at 10:33 AM ---------- Previous update was at 10:31 AM ----------

Done.
cat Myperlclass.pm

package Myperlclass;
sub new{
    my $class;
    $class=shift;
    my $self={
        a=>shift,
        b=>shift,
    };
    bless $self,$class;
    return $self;
}
sub add{
    my ($vr,$a,$b)=@_;
    my $res;
    $res=$vr->{a}+$vr->{b};
    print "res: $res\n";
}

cat b.pl

#!/usr/bin/perl

use Myperlclass;
$obj=new Myperlclass(4,5);
$obj->add();