var Buttons = {
	id : new Array(),
	buttonImages : new Array(),
	buttonImagesHover : new Array(),
	count : 0,

	addImage : function(id, standard, hover) {
		this.id[this.count] = id;
		this.buttonImages[this.count] = standard;
		this.buttonImagesHover[this.count] = hover;
		this.count++;
	},

	changeImage : function(id, mode) {
		var pos = -1;
		for (z=0; z<this.count; z++) {
			if (this.id[z] == id) {
				pos = z;
			}
		}
		if (pos < 0) {
			return;
		}
		var img = document.getElementById(id);
		if (typeof img != 'undefined') {
			if (mode == 'hover') {
				img.src = this.buttonImagesHover[pos];
			} else {
				img.src = this.buttonImages[pos];
			}
		}
	}
};