Untitled

<?php
 session_start();
 if (isset($_SESSION['admin'])) {
      header('location:admindash.php');
  }
  else{
    header('location:login.php');
  }
include('header.php');
 ?>
 <body background="../bgimage.jpg">

 <div class="container">
        <div id="loginbox" style="margin-top:50px;" class="mainbox col-md-6 col-md-offset-3 col-sm-8 col-sm-offset-2">
            <div class="panel panel-info" >
                    <div class="panel-heading">
                        <div class="panel-title text-center">Login for Admin</div>
                        <div style="float:right; font-size: 80%; position: relative; top:-10px"><a href="#"></a></div>
                    </div>

                    <div style="padding-top:30px" class="panel-body" >

                        <div style="display:none" id="login-alert" class="alert alert-danger col-sm-12"></div>

                        <form id="loginform" class="form-horizontal" role="form" method="post" action="login.php">

                            <div style="margin-bottom: 25px" class="input-group">
                                        <span class="input-group-addon"><i class="glyphicon glyphicon-user"></i></span>
                                        <input id="login-username" type="text" class="form-control" name="uname" value="" placeholder="username or email">
                                    </div>

                            <div style="margin-bottom: 25px" class="input-group">
                                        <span class="input-group-addon"><i class="glyphicon glyphicon-lock"></i></span>
                                        <input id="login-password" type="password" class="form-control" name="password" placeholder="password">
                                    </div>


                            <div class="input-group">
                                      <div class="checkbox">
                                        <label>
                                          <input id="login-remember" type="checkbox" name="remember" value="1"> Remember me
                                        </label>
                                      </div>
                                    </div>


                                <div style="margin-top:10px" class="form-group">
                                    <!-- Button -->

                                    <div class="col-sm-12 controls">
                                      <input id="btn-login" class="btn btn-success" type="submit" name="submit" value="login">

                                    </div>
                                </div>


                                <div class="form-group">
                                    <div class="col-md-12 control">
                                    </div>
                                </div>
                            </form>


                        </div>
                    </div>

 </body>
 </html>
 <?php
include('../dbcon.php');
if (isset($_POST['submit'])) {

    $username = $_POST['uname'];
    $password = $_POST['password'];
    $qry = "SELECT * FROM `login` WHERE `uname`='$username' AND `password`='$password' ";
    $run = mysqli_query($dbcon,$qry);
    $row = mysqli_num_rows($run);
    if ($row<1)
    {
       ?>
       <script type="text/javascript">alert('username and password does not match');
window.open('login.php','_self')
   </script>
       <?php

    }
    else{
         $data = mysqli_fetch_assoc($run);
        $id  = $data['id'];
        $_SESSION['admin'] = $id;
        header('location:admindash.php');
    }
}


  ?>

if (isset($_SESSION['admin'])) {
  header('location:admindash.php');
}
else{
  header('location:login.php'); // here
}

if (isset($_SESSION['admin'])) {
  header('location:admindash.php');
}