Thread: Register Plus Hidden Fields

Register Plus Hidden Fields

There are several hidden fields that are editable in Step 1, 2, and 3 of posting an ad.

For example, from step1.php:
<input type="hidden" id="cat" name="cat" value="<?php echo $_POST['cat']; ?>" />
<input type="hidden" id="catname" name="catname" value="<?php echo $_POST['catname']; ?>" />
<input type="hidden" id="fid" name="fid" value="<?php if(isset($_POST['fid'])) echo $_POST['fid']; ?>" />
<input type="hidden" id="oid" name="oid" value="<?php echo $order_id; ?>" />

I'm worried about people changing these before posting. How can I change this?.