gistfile1.php

<?php
$cadID = $_GET['cadID']; // validate this!
$url = '/uploads/';

$dbc = mysqli_connect('localhost','***********','************','*********')
or die ('Error connecting to Database');

$statement = mysqli_prepare($dbc, "UPDATE classifieds SET img1=? WHERE cadID=?;");
$statement->bind_param("s", $url . $ret); // $ret is not found in the given scope
$statement->bind_param("s", $cadID);

$result = statement->execute() or die('MySQL Error: ' . mysqli_error($dbc));