<?php     $key = $_GET['key'];                        //获得关键字     $select = $_GET['select'];                  //获得搜索引擎的选择     switch($select)                             //根据搜索引擎的不同跳转到不同的页面     {         case "google":                          //GOOGLE             $url = "http://www.google.com/search?q=".$key;             header("Location: $url");             break;         case "yahoo":                           //YAHOO             $url = "http://search.yahoo.com/search?p=".$key;             header("Location: $url");             break;         case "baidu":                           //百度             $url = "http://www.baidu.com/s?wd=".$key;             header("Location: $url");             break;         default:                                //如果搜索引擎不存在，结束程序             break;     } ?>