//寫前讀取已存在的訊息
$sql="select * from talkdata order by sn;";//欄位最好有兩欄(sn、name)以便判斷,sn欄位最好是auto_increment格式
$result=mysql_query($sql,$link_ID);
$num=mysql_num_rows($result);
for($i=0;$i<$num;$i++) {
$arr[$i]=mysql_fetch_array($result);
};
if($setsubmit=="OK" and $name!=""){//判斷是否有送出表單
if($num>=5) {
$deletedata=$arr[0][sn];
$sql2="delete from talkdata where sn='$deletedata';";//刪掉最前面的
$result2=mysql_query($sql2,$link_ID);
};
$sql3="insert into talkdata (name) values ('$name');";//刪完後再寫入
$result3=mysql_query($sql3,$link_ID);
$setsubmit="";
$name="";
};
$sql="select * from talkdata order by sn;";//寫後讀取
$result=mysql_query($sql,$link_ID);
$num=mysql_num_rows($result);
for($i=0;$i<$num;$i++) {
$arr[$i]=mysql_fetch_array($result);
};
?>
<html>
<body>
//訊息顯示
or die(mysql_error());
