<script type="text/javascript">     
function shapka(n)     
{document.write('<img border="0" src="/logo/'+n+'.gif">');}     
var h=(new Date()).getHours();     
if (h > 23 || h <7) shapka('1');     
if (h > 6 && h < 12) shapka('2');     
if (h > 11 && h < 19) shapka('3');     
if (h > 18 && h < 24) shapka('4');     
</script>