A : good morning sir/madam. can i help you?
B : good morning, i want to buy stamps, please. which is the correct counter?
A : This/That is the counter?
B : Thank/That is the counter.
A : Here you are.
B : Can i have six airmail envelopes, please?
A : Will you be sending any airmail?
B : Yes, please. How mush does it cost?
A : It's 25 Baht.
B : Here you are.
A : Thank. Here is your receipt.
B : thanks.
A : Your're welcome.