When I submit my form empty, instead of giving me an error msg for the name,email, etc; it gives me an error for the Original price. What am I doing wrong here? is there an easier way?

<?php
if ($name == "" or $email == "" or $phone == "" or $time == "") { ?> <script type="text/javascript"> alert("Please don't forget your personal info: Name, Email, Number, and best time to contact you."); history.back(); </script> <?php }

if (!$hidden == "") { ?> <script type="text/javascript"> alert("You have submitted your information in error. Please submit again."); history.back(); </script> <?php }

if ($org_price == ""){ ?> <script type="text/javascript"> alert("Please input Original note price."); history.back(); </script> <?php }

if ($down_payment == ""){ ?> <script type="text/javascript"> alert("Was there a down payment?"); history.back(); </script>; <?php }