when to show 1-134 and invitation letter to VISA OFFICER

[SWAILAM]

DEAR ALL
please advice me that when should i hand over my I-134 alongwith invitation letter and congress man letter of assurance( I recieved from my brother) to visa officer
1. at the initial stage when handing over my passports to VO
2. in the middle once he asks
3. or as adivced by any good senior member here
please advise action

regards
Swailam

[SWAILAM]

Dear Brothers

i am still waiting for your replies. hope you guys wll reply.


Swailam

[usvisitor1]

Documents should be shown only if asked for