Buy-Now.php

<?php
    include_once("header.php");
?>
    <div class="container od">
        <header class="odd">
            <h1>Cake Order Now</h1>
        </header>
        <form class="order-form" name="info" onsubmit="Valid()" method="post">
            <div class="form-group">
                <label for="name">Your Name:</label>
                <input type="text" id="name" name="name" autofocus placeholder="Enter your name">
            </div>

            <div class="form-group">
                <label for="address">Delivery Address:</label>
                <textarea id="address" name="address" rows="4"
                    placeholder="Enter your delivery address" minlength="20" maxlength="40"></textarea>
            </div>

            <div class="form-group">
                <label for="phone">Phone Number:</label>
                <input type="tel" id="phone" name="phone" placeholder="Enter your phone number" min="10" max="10" pattern="[7-8-6-9]{1},[0-9]{9}">
            </div>

            <div class="form-group">
                <label for="delivery-date">Select Delivery Date:</label>
                <input type="date" id="delivery-date" name="delivery-date">
            </div>

            <a href="./ordered.php"><input type="submit" value="Place Order"></a>
            <!-- <button class="submit-btn">Place Order</button> -->
        </form>
    </div>
    <script>
        function Valid(){
            if(document.info.name.value == ""){
                alert("Please Enter Valid Name");
                return false;
            }
            if(document.info.address.value == ""){
                alert("Please Enter Valid Address");
                return false;
            }
            if(document.info.phone.value == ""){
                alert("Please Enter Valid Mobile number");
                return false;
            }
            if(document.info.delivery-date.value == ""){
                alert("Please Enter Valid Date");
                return false;
            }
            return true;
        }
    </script>
</body>

</html>