open files in a directory

[homedw]

hi all,

i want to open some files in a directory, you can see the details below,

#!/usr/bin/perl -w
use strict;
opendir (FH,'C:\Player');
chdir 'C:\Player';
for my $file(readdir FH)
{
        open DH,"$file";
        foreach my $line(<DH>)
        {
                while($line=~/"a=(\d),b=(\w+)"/gi)
                {
                $sum+=$2-$1;
                }
         }
}
print "$sum\n";


I can't open the files in 'C:\Player', can you help me find out where the
problem is?

thanks,
Jack