Howdy, I am trying to get the image on the page below

Howdy,

I am trying to get the image on the page below to have the women's head showing when the page loads then reveal more of the bottom of the picture when scrolling down the page. (I've tried playing with the row height as well).

I tried this with no luck:

.ballons {
background-position: center top;
}

Page:
http://m24.siteground.biz/~websi541/joycebarwis.com/services/

Cheers,
Casper