$frameno  = "1";
$drawerno = "12";
$tempno   = "44";

# assignment
$framearray->{$frameno}{$drawerno} = $tempno;

# reassignment
%new_hash = %{$framearray};

# or only particular hashes thereof
%some_frame = %{ $framearray->{$frameno} };

# Now if we loop through %some_frame our keys are
# $drawerno and our values are the values assigned above

while ( ($drawer,$val) = each(%some_frame) ) {
   print "$drawer -> $val\n";
}

# would print
# 12 -> 44