Np.
if(ekran == 144x900) { <style type="text/css">body {background-image: tapeta_1440x900.jpg;}</style> }
if(ekran == 144x900) { <style type="text/css">body {background-image: tapeta_1440x900.jpg;}</style> }
<script language="JavaScript"> var szerokosc = screen.width; var wysokosc = screen.height; tlo = new Image(); tlo.src="szajs/gtaiv_bg_"+szerokosc+"x"+wysokosc+".jpg"; document.getElementById('gtaiv_bg').background=tlo.src; </script>