Page 1:
<form action='page2.php' method=post>
<select name=something onchage='update_stuff()'>
<option value=1>Car</option>
<option value=2>Truck</option>
...etc...
</select>
<input type=submit>
</form>
Page 2:
<form action='details.php'>
<select name=more_info>
<?PHP print_options( $HTTP_POST_VARS['something'] ); ?>
</select>
<input type=submit>
</form>
The part that you'll be most concerned with is writing a simple function called "print_options()".
Above your form, try putting this:
<?PHP
function print_options( $type )
{
for( $x=1; $x<10; $x++ )
{
echo "<option value=$x>Select $x</option>\n";
}
}
return;
}
?>
Only instead if printing numbers 1..10, you'll probably want to print something more interesting, probably something coming from a database.
Databases are beyond the scope of this question, but this should get you started.
HTH!
--Robert
