注册并登录php代码

Question

我正在使用php和mysql编写注册和登录程序。注册部分工作正常，但当我尝试使用有效凭据登录时，根据注册时存储的deatils，我仍然得到无效的注册码和密码。这是代码：

<?php
 session_start();
 require_once 'dbconnect.php';

 if (isset($_SESSION['userSession'])!="") {
 header("Location: studentportal.html");
 exit;
 }

if (isset($_POST['btn-login'])) {

 $Regnumber = strip_tags($_POST['Regnumber']);
 $Password = strip_tags($_POST['Password']);

 $Regnumber = $DBcon->real_escape_string($Regnumber);
 $Password = $DBcon->real_escape_string($Password);

  $query = $DBcon->query("SELECT Sessionid, Regnumber, Password FROM      regstudents WHERE Regnumber='$Regnumber'");
  $row=$query->fetch_array();

  $count = $query->num_rows; // if email/password are correct returns          must be 1 row

 if (password_verify($Password, $row['Password']) && $count==1) {
 $_SESSION['userSession'] = $row['Sessionid'];
header("Location: home.php");
 } else {
 $msg = "<div class='alert alert-danger'>
 <span class='glyphicon glyphicon-info-sign'></span> &nbsp; Invalid     Regnumber or Password !
</div>";
  }
 $DBcon->close();
 }
?>