HTML: <script language=JavaScript> function winload() { jsvnetleft.style.top=160; jsvnetleft.style.left=5; jsvnet_right.style.top=160; jsvnet_right.style.right=5; } if(document.body.offsetWidth>800){ { if(document.body.offsetWidth>800){ { document.write("<div id=jsvnetleft style='position: absolute;visibility:visible;z-index:1'>此处放左边的广告代码</div>" +"<div id=jsvnet_right style='position: absolute;visibility:visible;z-index:1'>此处放右边的广告代码</div>"); } winload() } } winload() } </script>