$coon = @mysqli_connect('127.0.0.1','root','root') or die("error connecting");
    mysql_query("set name 'utf8'");
    mysql_select_db('user');
    $sql="select * from user_login where username ='$username' and password= '$password'";
    $result = mysql_query($sql,$coon);
    $row = mysql_fetch_array($result);
    if($row){
        echo "success";
    }   
    else{
        echo"faile";
    }
    break;

救命错误显示，怎么改，在线等。。。