function getRandomInt(min, max) { 
	return Math.floor(Math.random() * (max - min + 1) + min);
}

function init(){
	var randomImage = "url(http://www.bentonwi.us/cogs/random" + getRandomInt(0, 6) + ".jpg)";
	//var randomImage = "url(http://www.bentonwi.us/cogs/land.jpg)";
	document.getElementById("randomImg").style.backgroundImage = randomImage;
}

window.onload = init;