Ajax代码和PHP单选输入有什么问题？

Question

In this code I can not get the radio input value to use for updating the database:

<script type="text/javascript">
function getVote() {
  if (window.XMLHttpRequest) {
    // code for IE7+, Firefox, Chrome, Opera, Safari
    xmlhttp=new XMLHttpRequest();
  } else {  // code for IE6, IE5
    xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
  xmlhttp.onreadystatechange=function() {
    if (xmlhttp.readyState==4 && xmlhttp.status==200) {
      document.getElementById("poll").innerHTML=xmlhttp.responseText;
    }
  }
  var vote = $('input[name=optionid]:checked').val();
  xmlhttp.open("GET","poll_vote.php?vote="+vote);
  xmlhttp.send();
}

on the same file the code is:

$options = mysql_query ("select * from options where pollid='poll'");
                while ($row1 = mysql_fetch_array($options))
                {   $id = $row1['id'];
                    $option = $row1['choice'];
                    $votes = $row1['votes'];
                        echo '<form id="poll">';
                        echo '<input type="radio" name="optionid" value="'.$id.'" onclick="getVote()" /><span>'.$option.'</span><br />';
                }

                        echo '</form>';

How to get checked radio value to use it on the other page "poll_vote.php"? By the way options used by the input radio are 3.

Answer 1

Obviously I do not know if there are other problems , but with these two changes should be tested what happens, and maybe it works.

Javascript

function getVote() {
  if (window.XMLHttpRequest) {
    // code for IE7+, Firefox, Chrome, Opera, Safari
    xmlhttp=new XMLHttpRequest();
  } else {  // code for IE6, IE5
    xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
  xmlhttp.onreadystatechange=function() {
    if (xmlhttp.readyState==4 && xmlhttp.status==200) {
      document.getElementById("poll").innerHTML=xmlhttp.responseText;
    }
  }
  var vote = $(this).attr('value');
  alert('your vote: ' + vote); // WITH THIS CHECK IF THE VOTE IS CORRECT
  xmlhttp.open("GET","poll_vote.php?vote="+vote);
  xmlhttp.send();
}

PHP

$options = mysql_query ("select * from options where pollid='poll'");

echo '<form id="poll">';

while ($row1 = mysql_fetch_array($options))
{   $id = $row1['id'];
    $option = $row1['choice'];
    $votes = $row1['votes'];
    echo '<input type="radio" name="optionid" value="'.$id.'" onclick="getVote()" /><span>'.$option.'</span><br />';
}

echo '</form>';

Answer 2

The problem I notice with the is this line, echo '<form id="poll">'; , is repeatedly printed as many as the return number of rows.

In the browser you have,

<form id="poll">
  <input type="radio" name="optionid" value="<?php echo $id; ?>" onclick="getVote()">
<form id="poll">
  <input type="radio" name="optionid" value="<?php echo $id; ?>" onclick="getVote()">
<form id="poll">
  <input type="radio" name="optionid" value="<?php echo $id; ?>" onclick="getVote()">
<form id="poll">
  <input type="radio" name="optionid" value="<?php echo $id; ?>" onclick="getVote()">
<form id="poll">
  <input type="radio" name="optionid" value="<?php echo $id; ?>" onclick="getVote()">
.
.
.

It happens you a number of repeated forms, before this closing tag

</form>

I offer you arrange your code in this way, for better analysis

<?php $options = mysql_query ("select * from options where pollid='poll'"); ?>
<form class="" id="poll" action="" method="post">
<?php while ($row1 = mysql_fetch_array($options)): ?>
  <?php
    $id     = $row1['id'];
    $option = $row1['choice'];
    $votes  = $row1['votes'];
  ?>
  <input type="radio" name="option<?php echo $id; ?>" value="<?php echo $id; ?>" onclick="getVote()">
  <span><?php echo $option; ?></span>
<?php endwhile; ?>
</form>

And will print your form like this,

<form id="poll">
  <input type="radio" name="option1" value="<?php echo $id; ?>" onclick="getVote()">
  <input type="radio" name="option2" value="<?php echo $id; ?>" onclick="getVote()">
  <input type="radio" name="option3" value="<?php echo $id; ?>" onclick="getVote()">
  <input type="radio" name="option4" value="<?php echo $id; ?>" onclick="getVote()">
</form>

notice this part name="option<?php echo $id; ?>" ? I made it like that so that you can have unique variable for every radio button, and don't forget to make your form like this <form class="" id="poll" action="" method="post"> so that you sent data via method post.

It may not be the solution, I hope this would help.