In your example,
the script always find just one line with the 'two' keyword and the same id from the log file.

So you never go inside the

if ( defined($lookup{$refs}) && $lookup{$refs} + $time_delta <= $t
+imestamp )
[download]

statement and there is no output.

And $lookup{$refs} + $time_delta is always greater than $timestamp

Maybe it's different in your real log file ?

hth,

PooLpi