Undefined index from a drop down box using jQuery - php

Question

I cannot seem to get the value from my dropdown box which is using JQuery linked up to my database, into an SQL statement?
Where is the error?
Thanks
Here is my PHP:
<form action="" method="post">
<p class="timetable-p">Room code:
<select id="combobox" name="combobox">
<form action="" method="post"><?php
echo '<option class="option">Type/Select a room</option>';
while ($row = $res->fetchRow()) {
$code = $row['roomcode'];
$titles[] = $row['park'];
echo '<option class="option" name="codedrop">'.$code.'</option>';
}
?>
<input type="submit" value="subm" name="subm">
</form>
<?php
if( isset( $_POST['subm'] ) )
{
$codedropOption= $_POST['codedrop'];
$resql = "SELECT * FROM 'ROOMS' WHERE 'roomCode' LIKE '$codedrop%'";
$res1 = mysql_query($resql);
echo "<table>";
while($row = mysql_fetch_array($res1)){
echo "<tr><td>" . $row['roomCode'] . "</td>";
echo "<td>" . $row['Style'] . "</td><td>" . $row['dataProjector'] . "</td>";
echo "<td>" . $row['Whiteboard'] . "</td><td>" . $row['OHP'] . "</td>";
echo "<td>" . $row['wheelchairAccess'] . "</td>";
echo "<td>" . $row['lectureCapture'] . "</td>";
echo "<td><input type='radio' name='radioSelect' value= '". $row['roomCode']."'></td>";
}
echo "</table>";
}
?>
</form>

Answer 1

1) Remove name="codedrop" from <option> Like
echo '<option class="option">'.$code.'</option>';
N.B.: Only <select> bears the name attribute, not <option>.
2) Remove first <form>, it's of no use. And even, nested <form> are not allowed.
3) Change
$codedropOption= $_POST['codedrop'];
To
$codedropOption= $_POST['combobox'];
to not get
Undefined index: codedrop
4) Change
$resql = "SELECT * FROM 'ROOMS' WHERE 'roomCode' LIKE '$codedrop%'";
To
$resql = "SELECT * FROM ROOMS WHERE roomCode LIKE '$codedrop%'";
Use backtick in place of single quotes '.
5) Change
$resql = "SELECT * FROM 'ROOMS' WHERE 'roomCode' LIKE '$codedrop%'";
To
$resql = "SELECT * FROM ROOMS WHERE roomCode LIKE '$codedropOption%'";
Updated Code
<form action="" method="post">
<p class="timetable-p">Room code:
<select id="combobox" name="combobox">
<?php
echo '<option class="option">Type/Select a room</option>';
while ($row = $res->fetchRow()) {
$code = $row['roomcode'];
$titles[] = $row['park'];
echo '<option class="option">'.$code.'</option>';
}?>
</select>
<input type="submit" value="subm" name="subm">
</form>
<?php
if( isset( $_POST['subm'] ) )
{
$codedropOption= $_POST['combobox'];
$resql = "SELECT * FROM ROOMS WHERE roomCode LIKE '$codedropOption%'";
$res1 = mysql_query($resql);
echo "<table>";
while($row = mysql_fetch_array($res1)){
echo "<tr><td>" . $row['roomCode'] . "</td>";
echo "<td>" . $row['Style'] . "</td><td>" . $row['dataProjector'] . "</td>";
echo "<td>" . $row['Whiteboard'] . "</td><td>" . $row['OHP'] . "</td>";
echo "<td>" . $row['wheelchairAccess'] . "</td>";
echo "<td>" . $row['lectureCapture'] . "</td>";
echo "<td><input type='radio' name='radioSelect' value= '". $row['roomCode']."'></td>";
}
echo "</table>";
}
?>