Remembering the value of a option box

The following code produces a dynamic dropdown box.

<select name="parent">
    <?php 
    $q = $admindb->getParentCategories();
    while($row=mysql_fetch_assoc($q)){
        $title=$row['title'];
        $catid=$row['id'];
        ?>
        <option value="<?php echo $catid; ?>"><?php echo $title; ?></option>
        <?php
    }   
    ?>
</select>

However, if the form is returned to the user with validation 开发者_Go百科errors, I need the box to remember the previous selection..

When using a text box, I have used the following code to remember the entry..

<input type="text" name="title" value="<?php echo $form->value("title"); ?>">

How would I add what is in that value tag to the select code?

Thanks

Change your option line to:

<option value="<?php echo $catid; ?>"<?php if($catid == $form->value("fieldname") echo 'selected="selected"'; ?>><?php echo $title; ?></option>

You have to use the selected attribute:

    <option value="<?php echo $catid; ?>"
        <?php if ($_GET['parent'] === $catid): echo 'selected'?>><?php echo $title; ?></option>

If you write XHTML, use selected="selected".

You need to add selected="true" to the correct option like this:

<select name="parent">
    <?php 
    $q = $admindb->getParentCategories();
    while($row=mysql_fetch_assoc($q)){
        $title=$row['title'];
        $catid=$row['id'];
        ?>
        <option value="<?php echo $catid; ?>" <?php if ($catid == $form->value("title")) { echo ' selected="true"';} ?>><?php echo $title; ?></option>
        <?php
    }   
    ?>
</select>