if (document.styleSheets) {

	var imgs = new Array("top_image.jpg", "top_image1.jpg", "top_image2.jpg");
	
	var rnd = Math.floor(Math.random() * (imgs.length));
	var selector = "div.head_image_center";
	var declaration = "background-image: url('/files/images/top/" + imgs[rnd] + "')";
	
	if (document.createStyleSheet) {
		
		var css = document.createStyleSheet();
		css.addRule(selector, declaration);
	}
	else {
	
		var cssText = selector + " { " + declaration + "; }"
		var head = document.getElementsByTagName("head")[0];
		var css = document.createElement("style");
		css.setAttribute("type", "text/css");
		css.setAttribute("media", "screen");
		
		if (typeof css.innerText != "undefined") css.innerText = cssText; else css.innerHTML = cssText;
		
		head.appendChild(css);
	}
}