Changing a perl script for hardcoding paths

Hi guys!

One of you kind geniuses (ozo) on here helped me with the following code :>)

----------------------------------------------------------------------------------- update.pl

#!/usr/bin/perl
my $dir = shift;
chdir($dir) or warn $!;
($prefix = $dir) =~ s/.*[\/\\]//;
my $i=join'',map{qq(
<img width="150" height="50" SRC="$prefix/$_" onMouseover="showImg('$prefix/$_')" onMouseout="showImg('')"><br>
)} <*.jpg>;

$^I=".bak";
$/='<!-- REMOVE EVERYTHING ABOVE THIS LINE BUT LEAVE THIS LINE INTACT -->';
while( <> ){
      s/(<!-- REMOVE EVERYTHING BELOW THIS LINE BUT LEAVE THIS LINE INTACT -->.*)[\s\S]*($\/)/$1$i$2/;
      print;
}
-------------------------------------------------------------------------------------------------- Syntax:

update.pl <full_path_to_folder> <file_to_be_manipulated>

What Id like to be able to do is to change this so instead of having to place the 2 args in, i simply run:

update.pl

The reason I want to do this is because the folder name and file name will always be the same, and where I place the update.pl script, is in the following hierarchy...

update.pl
index.html       (same folder as update.pl)
/thumbs          (contains my images)

So what id like is the following..

1) Run
update.pl

2) update.pl automatically looks at /thumbs folder (a subfolder below update.pl)

3) then update.pl updates index.html which is sitting in the same folder as update.pl

So, if i copy

update.pl
/thumbs
index.html

and then run update.pl

It updates the index.html in the same folder update.pl has been run from.

Any help greatly appreciated.

In the thumbs folder, I have named the images as follows..

001_<anynamehere>.jpg
002_<anynamehere>.jpg
003_<anynamehere>.jpg
etc
etc


Ideally guys also, if its possible, when update.pl gets the list of images from the thumbs directory, all the images will be written in sequence as per by number (the first 4 digits I have added to the filename)

001_
002_
etc
etc

that is, in order by number.

Thank you.