从另一个下拉列表的值显示下拉列表的特定值

Question

How to get the scheduleID value from a comboBox within a specific MovieID value from another comboBox?

comboBox Movie

<?php       
$query = "select * from ref_movies ORDER BY MovieID";
$result = mysql_query($query) or die (mysql_error());

echo '<select name="MovieID" ><option value="">---Select Movie---</option>';

while ($row = mysql_fetch_assoc($result))
{
    echo "<option value='" . $row['MovieID'] ."'>" . $row['MovieTitle'] ."</option>"; 
}
echo '</select>';
?>

comboBox Schedule

<?php
$query = "select * from schedule ORDER BY scheduleID";
$result = mysql_query($query) or die (mysql_error());

echo '<select name="ScheduleID" ><option value="">---Select Time---</option>';

while ($row = mysql_fetch_assoc($result))
{
    echo "<option value='" . $row['ScheduleID'] ."'>" . $row['MovieDATETIME'] ."</option>"; 
}
echo '</select>';
?>

Answer 1

Put the two PHP scripts in separate files.

Set the form action in the first one to the URL of the second one.

Read the value from $_GET['MovieID'] .