在我的数据库中，我有 2 个表格，一张用于提问，一张用于回答。
现在，问题是当我单击答案并提交时，它应该在 div 的同一页面上显示它是否正确，单击它会显示它是否正确。
代码在这里：
<?php
session_start();
require_once("scripts/connect_db.php");
$arrCount = "";
if(isset($_GET['question'])){
$question = preg_replace('/[^0-9]/', "", $_GET['question']);
$output = "";
$answers = "";
$q = "";
$dv="";
$dv2="";
$singleSQL = mysql_query("SELECT * FROM questions WHERE id='$question' LIMIT 1");
while($row = mysql_fetch_array($singleSQL)){
$id = $row['id'];
$thisQuestion = $row['question'];
$type = $row['type'];
$subject =$row['subject'];
$exam =$row['exam'];
$explan =$row['explan'];
$question_id = $row['question_id'];
$s ='<strong>'.$subject.'</strong>';
$e ='<small>'.$exam.'</small>';
$q = '<h2>'.$thisQuestion.'</h2>';
$ex ='<div id="welcomeDiv" style="display:none;" class="expl" >'.$explan.'</div>';
$sql2 = mysql_query("SELECT * FROM answers WHERE question_id='$question' ORDER BY rand()");
while($row2 = mysql_fetch_array($sql2)){
$answer = $row2['answer'];
$correct = $row2['correct'];
$answers .= '<table class="table table-hover table-bordered"> <tr>
<td class="chk"><label style="cursor:pointer;"><input type="radio" name="rads" value="'.$correct.'">'.$answer.'</label></td>
</tr></table>
<input type="hidden" id="qid" value="'.$id.'" name="qid"><br />
';
$answer=$_POST[$correct];
if(isset($answer)&&$correct==1){
echo $dv.='<div style="display:none; color=green;" id="welcomeDiv" id="dv">Your answer '.$answer.' is correct</div>';}
else{
$dv2.='<div style="display:none; color=red;" id="welcomeDiv" id="dv2">Your answer '.$answer.' is worng</div>';}
}
$output = ''.$s.','.$e.''.$q.','.$dv.''.$dv2.''.$answers.''.$ex.'<input type="button" name="answer" value="check" onclick="showDiv();check_asnwer()" id="" />';
echo $output;
}
}
?>
我正在尝试它，但它向我显示了这样的错误：
Notice: Undefined index: 0 in F:\wamp\www\quiz\questions.php on line 38
Notice: Undefined index: 1 in F:\wamp\www\quiz\questions.php on line 38
Notice: Undefined index: 0 in F:\wamp\www\quiz\questions.php on line 38
Notice: Undefined index: 0 in F:\wamp\www\quiz\questions.php on line 38
我的代码有什么问题吗，请帮助我，我需要这个来完成我的项目。
预先感谢