错误：PHP登录到多个部门

我创建了一个login.html页面和一个login.php脚本。在脚本中，它将首先获取我们输入的用户名和密码，然后使用数据库检查用户名或密码是否存在，或者如果用户有效，则它将检查其装卸ID，并使用其装卸权限打开其页面，但问题是，无论他们所在的部门是什么，它始终都在打开管理页面。请帮助我。

这是我的login.html代码

 <form id="form1" name="form1" method="post" action="login.php">
      <div class="form-group col-md-6">
          <label class="sr-only" for="exampleInputEmail1">User Name: *</label>
          <input required type="text" class="form-control" id="username" name="username" placeholder="User Name: *">
        </div>
<div class="form-group col-md-6">
           <label class="sr-only" for="exampleInputEmail1">Password: *</label>
          <input required type="password" class="form-control" id="password" name="password"          placeholder="Password: *">
        </div>
        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
        <input id="submit" type="submit" class="btn btn-lg btn-primary" value="Submit" style="width: 130px"> 
      Forgot Username or Password ?</form>

login.php脚本

<?php
session_start();

ob_start();

$conn = mysqli_connect("localhost","root","","hct_db");
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }
 // Define $username and $password
$username=$_POST['username'];
$password=$_POST['password'];


// To protect MySQL injection (more detail about MySQL injection)
$username = stripslashes($username);
$password = stripslashes($password);
$username = mysqli_real_escape_string($conn, $username);
$password = mysqli_real_escape_string($conn, $password);
$sql="SELECT username, password FROM employee where username='".$username."' and      password='".$password."'";
$result=mysqli_query($conn,$sql);

// Mysql_num_row is counting table row
$count=mysqli_num_rows($result);

// If result matched $username and $password, table row must be 1 row
if($count==1){
$sql2="SELECT department FROM employee WHERE username='".$username."'";
$result2=mysqli_query($conn,$sql2);
   if($result2==1){

$_SESSION['username'] = $username;
$_SESSION['password'] = $password;
header("location:admin/index.php");
}
if ($result2==2){

$_SESSION['username'] = $username;
$_SESSION['password'] = $password;
 header("location:developer/index.html");
}
if ($result2==3){
$_SESSION['username'] = $username;
$_SESSION['password'] = $password;
header("location:sales/index.html");
}

   else {
    echo "Wrong Username or Password";
    }
    ob_end_flush();
    ?>