This is the front end
<section id="MiddlePart">
            <form >


                <b id="Login1"> Name </b>
                <input id="Login1"  type="text" name="txtName" value="" /></br>
                <b id="Login2"> Password </b>
                <input id="Login2" type="password" name="txtPassword" value="" />

                <input id="btnLogin" type="button" value="Login" />
            </form>
            <?php
            if (isset($_GET['btnLogin'])) {

                $formUsername = $_GET['txtName'];
                $formPassword = $_GET['txtPassword'];
                $connObj->LoginValidation($formUsername, $formPassword);

                if ($connObj->LoginValidation($formUsername, $formPassword)) {
                    header('location:AdminPage.php');

                }
            }
            ?>
        </section>

This is the function im recalling

function LoginValidation($user, $pass) {

        $query = "SELECT *  FROM  `logintable` WHERE `username` ='$user' AND `password` = '$pass' ";
        $result = mysqli_query($this->link, $query);
        $row = mysqli_fetch_array($result, MYSQLI_ASSOC);
          if (count($row) ==0)
       {
       return FALSE;
       }
 else {
             return TRUE;
       }

    }