Getting Current Session Number or Mode Number at runtime in ABAP.

Hello Experts,

  My issue is regarding getting the Current Session Number at runtime. I can open 6 Sessions at a time and want to get the session number of current opened  session. Here the Session Number I mean is  'MOD'  as given in following snapshot.

  So, if I open the VA12 transaction from Session 2 or MOD 2 as in the snapshot below , How can I get the Number '2' at runtime. 

I cannot use the FM TH_LONG_USR_INFO when using multiple VA12 transactions.

The Fig: FM TH_LONG_USR_INFO  output.