var randomImage = {
	image_container : Object,
	image_count : Number,
	init : function(image_count){
		this.image_container = document.getElementById('header_image_container');
		if(this.image_container != null){
			this.image_count = image_count
			this.displayImage();
		}
	},
	displayImage : function(){
		var current_image = this.image_container.style.backgroundImage;
		var new_image_number = this.getRandomNr();
		var new_image = current_image.replace('1',new_image_number);
		this.image_container.style.backgroundImage = new_image;
		//alert(new_image);
	},
	getRandomNr : function(){
		var number = Math.floor(Math.random() * (this.image_count+2));
		if(number == 0){
			number++
		}
		return number;
	}
}

window.onload = function(){
	randomImage.init(5);
}