function RandomImg(numberImgs) {
	var imgBaseName = "images/home_middle";
	var imgExt = ".gif";
	
	var randomNum = Math.round((Math.random() * (numberImgs + 1)));
		   
	
	//make sure number is not referencing negative array index
	if (randomNum <= 0) {
		randomNum += 1;
	}
	
	//make sure number is not greater than largest array index
	if (randomNum > numberImgs) {
		randomNum -= 1;
	}
	
	return imgBaseName + randomNum + imgExt;
}