what if case

Dear All
as i am experiencing a good time with flexsim and enjoying building all my projects on the software.
I passed in some bad times with the SQL.
I have one source (batch processing of 1350 units every 735 time unit )
connected to a queue (maximum size 1485) connected to a processor connected to a sink
I want the source to send a batch in only one case
If the queue size is less than 135 units, and this case happens every 735 time unit

to explain more
time 0 starting model with 1350 unit in the queue
time 735 queue size was 300 unit ( do not send a batch )
time 1470 queue size was 0 units ( send a batch )

so in this case the queue was empty for some time between 735 and 1470.


Can anyone help me how can I do this logic or how can it be done.

note: I am trying to learn the Logic of Flexscript in this software, but just started
Regards,


Hassan Elhajj