I have a 2003 Specialized Allez'. Yesterday, I went on a 20mi. ride. When I came back, I thought I should check the air in my tires. My tires have the Presta Valve. I started to try to pump back tire. All the air went out of it. Now I need to pump the tire back up again.

I have looked endlessly on the Net for instructions on the use of the Presta Valve and, I cannot find any good instructions on it.

I would be most greatful, if someone could point me in the right direction.

Christopher