How do I load movie's from a button?

Hi, I’m a total beginner when it comes to actionscript and wonder if anyone can help me out? Basically I’ve got to do a flash animation for a touch screen. The touch screen is connected to a vending machine that vends phone and tv cards for hospitals. My first problem is the buttons. When the user presses a button the button has to load a movie, I’m almost there but I keep getting a Syntax error so the button doesn’t work. Has anyone got any tutorials or actionscript which will let me load a movie when a button is pressed.
There are just two buttons on the machine a £5 and a £10 button. When you press the £5 button it leads to a movie which tells you to insert £5 credit. When the person inserts £5 there’s a credit window that tells you how much credit you’ve inserted, when there’s enough credit the movie continues to the last movie which says thankyou etc etc. How can I calculate the credit or how can I tell the credit window to load the final movie when there’s enough credit in the machine.

If anyone can help me I’d be really greatful, I’m really stuck at the moment and need help.

Andy