(PHP) 当字段为空白且 JavaScript 关闭时，从提交而不是显示错误消息

Question

<?php

if($_SERVER["REQUEST_METHOD"] == "POST"){


$Fname      =  $_POST["Fname"];
$Lname      =  $_POST["Lname"];
$email      =  $_POST["email"];
$address1   =  $_POST["address1"];
$address2   =  $_POST["address2"];
$city       =  $_POST["city"];
$state      =  $_POST["state"];
$zip_code   =  $_POST["zip"];
$phone      =  $_POST["phone"];
$distance   =  $_POST["distance"];


        //form php validation error massage for blank fields
        if($Fname == "" || $Lname == "" || $email == "" || $address1 == "" || $city == "" || $state == "" || $zip_code == "" || $phone == ""){
            $msg =  "<p class='error'>The required fields cannot be blank</p>"

    ;
            }
             if(!filter_var($email, FILTER_VALIDATE_EMAIL)  && !isset($msg)){ //email validation 
                     $msg = "<p class='error'>You must place a real email address</p>";
                    }else{
                            require_once("inc/admin_login.php");  //log in database file
                            $query = "INSERT INTO runner(fname,lname,email,address1,address2,city,state,postcode,phone,distance) VALUES('$Fname','$Lname','$email','$address1','$address2','$city','$state','$zip_code','$phone','$distance')";
                            $result=mysqli_query($con,$query);

                                if($result){  //if successfull logining in to database message
                                    $msg = "<h2 class='notice'>Thank You For Signing Up</h2>"; 
                                }else{
                                        $error_message  = mysqli_error($con);
                                        $result  = "There was an error: $error_message";
                                        exit($result);
                                }// end if
                            }//end else

                header("Location:signup.php?status=thankyou"); //redicrects you when comments are entered in correctly

    }// end of main 1st if

    $pageTitle="Sign Up";
    include("inc/header.php");
    include("inc/navigation.php");
?>


<div class="signupWrapper">
    <h1>Sign up to run</h1>
        <?php if(isset($msg)){  //where blank error message will display
                echo $msg;
            }if(isset($_GET['status']) && $_GET['status'] == "thankyou"){  // msg that displays on the redirect page if comments are entered correctly
                    echo "<p class='notice'>Thank you for submitting your comment</p>";
                }else{
            ?>
                <form  method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>" id="signUpForm" name="signUpForm" title="Sign To Race Form">
                    <table class="signUp">
                        <tr>
                            <th>
                                <label for="Fname">First Name:</label>
                            </th>
                            <td>
                                <input type="text" id="Fname" name="Fname"></input>
                            </td>
                        </tr>

                        <tr>
                            <th>
                                <label for="Lname">Last Name:</label>
                            </th>
                            <td>
                                <input type="text" id="Lname" name="Lname"></input>
                            </td>
                        </tr>

                        <tr>
                            <th>
                                <label for="email">Email:</label>
                            </th>
                            <td>
                                <input type="email" id="email" name="email"></input>
                            </td>
                        </tr>   

                        <tr>
                            <th>
                                <label for="address1">Address 1:</label>
                            </th>
                            <td>
                                <input type="text" id="address1" name="address1"></input>
                            </td>
                        </tr>

                        <tr>
                            <th>
                                <label for="address2">Address 2:</label>
                            </th>
                            <td>
                                <input type="text" id="address2" name="address2"></input>
                            </td>
                        </tr>

                        <tr>
                            <th>
                                <label for="city">City:</label>
                            </th>
                            <td>
                                <input type="text" id="city" name="city"></input>
                            </td>
                        </tr>

                        <tr>
                            <th>
                                <label for="state">State:</label>
                            </th>
                            <td>
                                <input type="text" id="state" name="state"></input>
                            </td>
                        </tr>

                        <tr>
                            <th>
                                <label for="zip">Zip Code:</label>
                            </th>
                            <td>
                                <input type="text" id="zip" name="zip"></input>
                            </td>
                        </tr>

                        <tr>
                            <th>
                                <label for="zip">Phone:</label>
                            </th>
                            <td>
                                <input type="text" id="phone" name="phone" title="enter phone number"></input>
                            </td>
                        </tr>

                        <tr>
                            <th>
                                <label for="">Distance:</label>
                            </th>
                            <td>
                                <fieldset>
                                <label for="distance1">1 Mile</label><input type="radio" id="distance1" name="distance" value="1mile" ></input>
                                <label for="distance2">5K</label><input type="radio" id="distance2" name="distance" value="5K" checked></input>
                                <label for="distance3">10K</label>  <input type="radio" id="distance3" name="distance" value="10K" ></input>
                                </fieldset>
                            </td>
                        </tr>

                        <tr>
                            <th>

                            </th>
                            <td>
                                <label for=""></label><input type="submit" id="submitForm" name="submitForm" value="Submit" title="submit button"></input>
                                <label for=""></label><input type="reset" id="clear" name="clear" value="Clear" title="clear button" ></input>
                            </td>
                        </tr>

            </table>
        </form>
            <?php }?>  <!-- ends the else statement above in the start of the form, to only show the thank you message/ thank redirect page if 
                        comments are entered in correctly  -->
</div>

Answer 1

检查一下

if($_SERVER['REQUEST_METHOD']=='POST')
{
  $Fname = $_POST['fnm'];
  $Lname = $_POST['lnm'];
  $email = $_POST['email'];

   if($Fname == "" || $Lname == "" )
   {
      $msg =  "<p class='error'>The required fields cannot be blank</p>" ;
   }
   else if(!filter_var($email, FILTER_VALIDATE_EMAIL))
   { 
      $msg = "<p class='error'>You must place a real email address</p>";
   }
   else
   {
      $msg = "<p class='error'>Form submition gose here</p>"; 
   }

   echo $msg;
}