airport checkin.

I have been to Vietnam 3 times this year. The last2 times I used your system which I think is great. You all met me when I came into the airport and within 15 minutes I was out and gone. Here is what I am afraid of and it really has nothing to do with you. Both times when I check-in at the airport here, both times with different airlines, the attendant wanted to refuse me because I didn't have my Visa in my hand. i showed them the packet and the letter from you explaining I would get it stamped In hcmc, they almost made me miss my flight. I had to have the Manager read my information and I thought even he was going to not except this. I'm just worried because I will be going again to Vietnam in august and I hope I get on a plane.