Frontier Man

You find an empty bar stool in between two soldiers. You plop yourself down into the seat and order yourself a beer. The bar tender pours you a large glass full of the fizzy drink and slides it down to you. You pick up the glass and take a large gulp of the beer. Being your first time to try the alcohol, it chokes you up a little. The two soldiers laugh a little at how well you handled the first drink. One of them slaps you on the back, "Son, I bet you can't finish that beer within the next ten seconds."

You are known for not being able to take a challenge. What are you gonna do?