var width;
width = window.innerWidth; 
if (width <= 1800 && width > 1280){
		document.write ("<link rel=\"stylesheet\" type=\"text/css\" href=\"./css/bg/bg1800.css\" />\n");
	}
else if (width <= 1280 && width > 1024){
		document.write ("<link rel=\"stylesheet\" type=\"text/css\" href=\"./css/bg/bg1280.css\" />\n");
	}
else if (width <= 1024 && width > 800) {
		document.write ("<link rel=\"stylesheet\" type=\"text/css\" href=\"./css/bg/bg1024.css\" />\n");
	}