login.php

<?php
   include("config.php");
   session_start();

   if($_SERVER["REQUEST_METHOD"] == "POST") {
      // username and password sent from form

      $myusername = mysqli_real_escape_string($db,$_POST['username']);
      $mypassword = mysqli_real_escape_string($db,$_POST['password']);

      $sql = "SELECT id FROM admin WHERE username = '$myusername' and passcode = '$mypassword'";
      $result = mysqli_query($db,$sql);
      $row = mysqli_fetch_array($result,MYSQLI_ASSOC);
      $active = $row['active'];

      $count = mysqli_num_rows($result);

      // If result matched $myusername and $mypassword, table row must be 1 row

      if($count == 1) {
         session_register("myusername");
         $_SESSION['login_user'] = $myusername;

         header("location: welcome.php");
      }else {
         $error = "<center><b>Your login username or password is invalid, or you have not entered a password nor a username.</b></center>";
      }
   }
?>
<html>
   <head>
      <title>OKRA Networks | Login</title>

      <style type = "text/css">
         body {
            font-family:Arial, Helvetica, sans-serif;
            font-size:14px;
         }

         label {
            font-weight:bold;
            width:100px;
            font-size:14px;
         }

         .box {
            border:#666666 solid 1px;
         }
      </style>

   </head>

   <body bgcolor = "#FFFFFF">

      <div align = "center">
         <div style = "width:300px; border: solid 1px #333333; " align = "left">
            <div style = "background-color:#343343; color:#FFFFFF; padding:4px;"><b><Login></b></div>

            <div style = "margin:30px">

               <form action = "" method = "post">
                  <center><label>Username  : </label><input type = "text" name = "username" class = "box"/><br /><br />
                  <label>Password  : </label><input type = "password" name = "password" class = "box" /><br/><br />
                  <input type = "submit" value = " Login "/><br /></center>
               </form>

               <div style = "font-size:11px; color:#cc0000; margin-top:10px"><?php echo $error; ?></div>

            </div>

         </div>

      </div>

   </body>
</html>