Unable to set background image in center column on one page

Hello all,

Wow, this started out to be something I thought was simple. After 3.5 hours, I need help. I've searched the forum, read every example I thought would be helpful, but nothing I've attempted has worked.

I'm using ATA 3.7.10. All I'm trying to do is set a background image for one page that has an ID of 49. I just need the image to display in the center column as a background. I've tried to set css in both the css/html inserts section, and the style & edit center column, but nothing works.

I (know) my url path is correct, the file name is correct, the image is there, but regardless the css coding, nothing displays.

I've tried so many css examples like below, but nothing:

.background {
background: url(http://localhost/NetMonkeys/images/crossroads.png;
}

#page-49 {
background-image: http://localhost/NetMonkeys/images/crossroads.png !important;
}

#body.page-id-49 td.middle{
background-image: url(http://localhost/NetMonkeys/images/crossroads.png)
}
I'm developing the site in a local wamp setup, so I can't show an example. Could someone please help me out?

Barry