Rate Calculator: Best way to place dollar sign in amount input field automatically?

Hi All,
I have a Rate Calculator I am building for my companies insurance products. You can see it now at http://newco.ratecal.info and any input for the password works at the moment.

If you choose either calculator you’ll have to place a desired amount of insurance. I’m trying to find the best way to place a dollar sign ($) in the input field after the user inputs an amount. This is purely cosmetic and in all honesty is a personal request from my boss. One which I could not seem to deter, hehe.

What is the easiest way to do this? I’m assuming javascript/jquery. But I’m limited in those areas, but have no problem picking up a book or reading some articles. Can anyone point me in the right direction?

Thanks!

Anyone?

How about using a dollar sign in the background image for the textbox then padding the input over?