var http_request=false;
  function send_request(url){//初始化，指定處理函數(shù)，發(fā)送請求的函數(shù)
    http_request=false;
//開始初始化XMLHttpRequest對象
if(window.XMLHttpRequest){//Mozilla瀏覽器
  http_request=new XMLHttpRequest();
  if(http_request.overrideMimeType){//設(shè)置MIME類別
    http_request.overrideMimeType("text/xml");
  }
}
else if(window.ActiveXObject){//IE瀏覽器
  try{
   http_request=new ActiveXObject("Msxml2.XMLHttp");
  }catch(e){
   try{
   http_request=new ActiveXobject("Microsoft.XMLHttp");
   }catch(e){}
  }
    }
if(!http_request){//異常，創(chuàng)建對象實(shí)例失敗
  window.alert("創(chuàng)建XMLHttp對象失??！");
  return false;
}
http_request.onreadystatechange=processrequest;
//確定發(fā)送請求方式，URL，及是否同步執(zhí)行下段代碼
    http_request.open("GET",url,true);
http_request.send(null);
  }
  //處理返回信息的函數(shù)
   function processrequest(){
   if(http_request.readyState==4){//判斷對象狀態(tài)
     if(http_request.status==200){//信息已成功返回，開始處理信息
   document.getElementById(reobj).innerHTML=http_request.responseText;
  }
  else{//頁面不正常
   alert("您所請求的頁面不正常！");
  }
   }
  }
   function checkfourm(obj){
    var f=document.fourm;
    var newfourm=f.newfourm.value;
    var username=f.username.value;
    var id=f.id.value;
    if(username==""){
           document.getElementById(obj).innerHTML="<img src=images/false.gif> <font color=red>您必須先登錄！</font>";
     return false;
    }
    else if(newfourm==""){
     document.getElementById(obj).innerHTML="<img src=images/false.gif> <font color=red>您還沒填寫評論內(nèi)容！</font>";
     return false;
    }
    else{
     document.getElementById(obj).innerHTML="正在發(fā)送數(shù)據(jù)...";
     send_request('sendnewfourm.php?username='+username+'&newfourm='+newfourm+'&id='+id);
     reobj=obj;
    }
   }

<?php
  header('Content-Type:text/html;charset=GB2312');//避免輸出中文亂碼，linux下不需要
  $username=trim($_GET['username']);
  $newfourm=trim($_GET['newfourm']);
  $id=$_GET['id'];
  $time=date("Y-m-d");

  include('inc/config.inc.php');
  include('inc/dbclass.php');
  $db=new db;//從數(shù)據(jù)庫操作類生成實(shí)例
  $db->mysql($dbhost,$dbuser,$dbpassword,$dbname);//調(diào)用連接參數(shù)函數(shù)
  $db->createcon();//調(diào)用創(chuàng)建連接函數(shù) 

  $addsql="insert into cr_fourm values(0,'$newfourm','$username','$time',$id)";
  $db->query($addsql);
  echo"<img src=images/pass.gif> <font color=red>評論已成功發(fā)表！</font>";
  //echo $addsql;
  $db->close();//關(guān)閉數(shù)據(jù)庫連接
?>

<table width="100%" border="0" cellspacing="0" cellpadding="0">
      <tr>
        <td align="center"><?php echo $rows_p[p_info];?></td>
      </tr>
      <tr>
        <td align="center"><br><br><iframe frameborder="0" scrolling="auto" src="showfourm.php?picid=<?=$id;?>" style=HEIGHT:250px;VISIBILITY:inherit;WIDTH:98%;Z-INDEX:2 ></iframe>
</td>
      </tr>
      <tr>
        <td align="center"><br><br>
  <div align="center" id="result"></div>
  <form name="fourm">
  <table width="100%" border="0" cellspacing="0" cellpadding="0">
          <tr>
            <td height="25"> 快速發(fā)表評論<span class="STYLE1">（必須先登陸）用戶名：
                <input name="username" type="text" value="<?=$username?>" readonly>
            </span></td>
          </tr>
          <tr>
            <td height="32" align="center" valign="middle"><textarea name="newfourm" class="f" id="newfourm"></textarea></td>
          </tr>
          <tr>
            <td height="32"> <input name="submit" type="button" value="發(fā)表評論" onClick="checkfourm('result')">
              <input name="reset" type="reset" id="reset" value="重新填寫">
            <input name="id" type="hidden" id="id" value="<?php echo"$id";?>"></td>
          </tr>
        </table>
        </form>
        </td>
      </tr>
    </table>