DIV+CSS（网页遮罩效果）
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head> <title></title> <style type="text/css"> #poplayer { position:absolute; top:100px; left:400px; width:300px; height:200px; z-index:8888; background-color:#9CAAC1; } #covered { position:fixed; _position:absolute z-index:888; top:0px; left:0px; width:100%; height:100%; background-color:Black; opacity:0.3; } </style></head><body> <input type="text" value="底层" /> <div id="covered"> </div> <div id="poplayer"> <input type="text" value="弹出层" /> </div></body></html>