## Background image change

Hi there,

I'm trying to change the background image of a page (with setInterval eventually, but this is just a button to test it for now). The background image is appearing fine, and the alternate image is nice.

Code:
`<body style="background-image:url('img/backg.jpg'); background-size: 100%; background-repeat:no-repeat; background-color: #8ba49e;" onload="backg();">`
then this later on in the body:

Code:
`<input type="button" value="button" onclick="document.body.style.backgroundImage = 'img/backg1.jpg';">`
It's not working. I've also had referred to the background image in onclick as [ICODE]document.body.background[/ICODE] and [ICODE]document.body.backgroundImage[/ICODE].

What's gone wrong?