I am stuck with a javascript program and I was hoping someone here can point me in the right direction.

Basically, I have an HTML page with list of about 20 items, each with a specific dollar amount. I need to make it so that there is a checkbox by each item, and when someone comes to the page and selects items, it adds up the dollar amount for all items checked and displays that amount at the bottom of the page. Pretty simple in concept, but I am having a hard time figuring out how to program it.

Something like this is what I am looking for:

The only problem in me using that is I get errors when I try to run it.

Does anyone know of a script like what I am looking for or can at least help me out with this? I am a javascript newbie.

Any help is appreciated!