var imageindex = 0;

function rotateImage() {
	intervalID = setInterval('imageindex = swapImage(imageindex)',3000);
}

function swapImage(imageindex) {

	var imageArray = new Array(
		'assets/houses/residential_001.jpg',
		'assets/houses/residential_002.jpg',
		'assets/houses/residential_003.jpg',
		'assets/houses/residential_004.jpg',
		'assets/houses/customhomes_001.jpg',
		'assets/houses/customhomes_002.jpg',
		'assets/houses/customhomes_003.jpg',
		'assets/houses/customhomes_004.jpg',
		'assets/houses/commercial_001.jpg',
		'assets/houses/commercial_002.jpg',
		'assets/houses/commercial_003.jpg'
		);

	imageindex++;
	
	if (imageindex > (imageArray.length - 1)) {
		imageindex = 0;	
	}
	
	var imgRotate = document.getElementById("imgRotate");
	
	imgRotate.src = imageArray[imageindex];
	
	return(imageindex);
}