http://www.adobe.com/products/flash/ Oh yeah...its not cheap.
I'm guessing you are pretty new to this since you didn't know what the program is to make Flash...but there is probably a lot to learn before you will be able to easily make a game. I say this not to get your hopes up on being able to get the program and make a game in 30 minutes or even 30 days. Try not to bite off more than you can chew and learning Flash will be a lot more fun. Try to make something far too advanced without any knowledge is like trying to run a marathon without having tried to do a mile (or km, depending on what system you believe in). Start with the basics,
http://www.codingforums.com/showthread.php?t=126424 and here are a bunch of sites with basic tutorials.
Before you post, read our: 
