MQL4 Detecting MT4 have completed Downloading of Outstanding/Historical Orders

 

In MT4, there exists a stage/state: when we switch from AccountA to AccountB, when Connection is established and init() and start() are triggered by MT4; but before the "blinnnggg" (sound) when all the historical/outstanding trades are loaded from Server.

Switch Account>Establish Connection>Trigger Init()/Start() events>Start Downloading of Outstanding/Historical trades>Completed Downloading (issue "bliinng" sound).

I need to know (in MQL4) that all the trades are completed downloaded from the tradeServer --to know that the account is truly empty -vs- still downloading history from tradeServer.

Any pointer will be appreciated. I've explored IsTradeAllowed() IsContextBusy() and IsConnected(). All these are in "normal" state and the init() and start() events are all fired ok. But I cannot figure out if the history/outstanding trade lists has completed downloading.

Reason: