hello everyone am really sorry i don't know perl and i have to debug this piece of code below can anybody who has time help me to understand the below code line-by-line please 
foreach $key (sort {$a <=> $b} $query->param()) {
next if ($key =~ /^\s*$/);
next if ($query->param($key) =~ /^\s*$/);
next if ($key !~ /^filetoupload_(\d+)$/);
$Number = $1;

if ($query->param($key) =~ /([^\/\\]+)$/) {
    $Filename = $1;
    $pxuser = $2;
    $Filename =~ s/^\.+//;
    $pxuser =~ s/^\.+//;
    $files{$Number} = $Filename;
    $File_Handle = $query->param($key);

if (!$ALLOW_INDEX && $Filename =~ /^index/i) {
     print header;

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In reply to help on this code below by sasidhardv

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