พี่คับอยากให้มัน alert เมื่อคนยังไม่ตอบข้อนี้ทำไงคับ
                    if(!empty($topicid)){
                      if (isset($_POST['submit'])) {
                        // print_r($_POST);       
                         //// CHECK TOPIC STATUS  ////
                          if($status == 'close' && $statusBlock == 'Block'){
                              die(" ไม่สามารถทำแบบสำรวจได้เพราะ หัวข้อสำรวจถูกปิดไม่ให้ใช้งานได้ <br>กรุณารอ 5 วินาทีเพื่อกลับไปหน้าแรก ".goTo('index.php','5')." ");
                          }
                          
                          //// CHECK TOPIC STATUS  //// 
                          
                               //// CHECK TOPIC Comment  //// 
                          if($Comments != '') {
                                 if(session_is_registered('userid'))
                                  {$sqlMemberAnswercustom = "INSERT INTO custom_answerAssess(TopicId, UserId, Date, Custom)VALUES($topicid, $userid, now(),'$Comments')";   
                                 mysql_query($sqlMemberAnswercustom);} 
                                 else
                                 {$sqlMemberAnswercustom = "INSERT INTO custom_answerAssess(TopicId, UserId, Date, Custom)VALUES($topicid, null, now(),'$Comments')";   
                                 mysql_query($sqlMemberAnswercustom);} }
                                 //// CHECK TOPIC Comment  //// 
                                 
                           $checkAnswer = "Select TopicId From Answer Where UserId = $userid And TopicId = $topicid"; 
                                  $resultCheck = mysql_query($checkAnswer); 
                                   //echo $checkAnswer;
                                   //if(mysql_num_rows($resultCheck)>0){
 //                                      die("ได้ทำแบบประเมินนี้ไปแล้ว ".goTo("index.php","3"));
 //                                  }  
                        
                             $quizids = $_POST['quizid'];
                              
                             foreach($quizids as $quizid){
                                $answer = $_POST[$quizid];
                                 
                                 
                              //   if(session_is_registered('userid')){
                                 
                                  $sqlMemberAnswer = "INSERT INTO Answer(TopicId, ChoiceId, QuestionId, UserId)VALUES($topicid, $answer, $quizid, $userid)";   
                                  mysql_query($sqlMemberAnswer);
                                  
                                 
                                 
                                 //echo "xx :".$answer."<br>";
                                 $sqlAnswer = 'UPDATE Choice SET Value = Value+1 WHERE ChoiceId = '.$answer; 
                                 //echo "<br>".$sqlAnswer;
                                 $result_answer = mysql_query($sqlAnswer);
                                 
                                 
                            // } 
                         /// Check Answer
                         mysql_query("UPDATE Topic SET CheckAnswer = '1' WHERE TopicId = $topicid");
                         if($result_answer){
                         //echo "success";
                                  
                                 
                                
                      }
                      else {
                         echo "fail";?>
                        <SCRIPT LANGUAGE="JavaScript">
                        <!-- Begin
                        alert("กรุณาตอบให้ครบทุกข้อ")
                        // End -->
 </script>
                                <?php }       
                      
                      }  
                    } if($result_answer){
                         //echo "success";
                                  
                                 
                                 echo "ขอบคุณค่ะ ที่ตอบ".goTo("index.php","12");
                      }
                      else {
                        
                                 } }  
                   
 
            
แนะนำให้ประยุกต์จากตัวอย่างที่ให้ไปนะครับ ถ้าคิดว่าทำไหว แนะนำให้ตรวจด้วย Javascript ก่อนส่งครับ