/*
 * randomImgs 1.0
 *
 * Copyright (c) 2008- passiona.net [Nagano, Japan]
 * 
 * Please refer "http://creativecommons.org/licenses/by/2.1/jp/"
 *
 * Required above jQuery JavaScript Library v1.3.2
 */
var randomBgImgs = {
	init: function(target, file, ext, num) {
		var tar = document.getElementById(target);
		var n = parseInt(Math.random()*num);
		var imgFile = file + n + ext;
		var d = document;
		
		$(tar).css("background-image", "url("+imgFile+")");
		/*高速化のため先読みなし
		for(var i=0; i<num; i++) {
			var img = file + i + ext;
			var img1 = {};
			d.img1 = new Image();
			d.img1.src = img;
		};
		*/
	}
};