How to fix this issue? I'm using AWS in php

[weich]

this is my error: This page contains the following errors:error on line 2 at column 1: Extra content at the end of the documentBelow is a rendering of the page up to the first error.I just copy the code from this site awshere's my code:\[code\] <?phpheader('Content-type: text/xml');function awsRequest($searchIndex, $keywords, $responseGroup = false, $operation = "ItemSearch", $pageNumber = 1){ $service_url = "http://ecs.amazonaws.com/onca/xml?Service=AWSECommerceService"; $associate_tag = "your-associate-tag"; $secret_key = "YOUR_SECRET_KEY"; $access_key = "YOUR_ACCESS_KEY"; // build initial request uri $request = "$service_url&Operation=$operation&AssociateTag=$associate_tag&SearchIndex=$searchIndex&Keywords=".urlencode($keywords)."&ItemPage=$pageNumber"; // parse request into params $uri_elements = parse_url($request); $request = $uri_elements['query']; parse_str($request, $parameters); // add new params $parameters['Timestamp'] = gmdate("Y-m-d\TH:i:s\Z"); $parameters['Version'] = $version; $parameters['AWSAccessKeyId'] = $access_key; if($responseGroup){ $parameters['ResponseGroup'] = $responseGroup; } ksort($parameters); // encode params and values foreach($parameters as $parameter => $value){ $parameter = str_replace("%7E", "~", rawurlencode($parameter)); $value = http://stackoverflow.com/questions/12593306/str_replace("%7E", "~", rawurlencode($value)); $request_array[] = $parameter . '=' . $value; } $new_request = implode('&', $request_array); // make it happen $signature_string = "GET\n{$uri_elements['host']}\n{$uri_elements['path']}\n{$new_request}"; $signature = urlencode(base64_encode(hash_hmac('sha256', $signature_string, $secret_key, true))); // return signed request uri return "http://{$uri_elements['host']}{$uri_elements['path']}?{$new_request}&Signature={$signature}";}// make the request$xml = simplexml_load_file(awsRequest("VideoGames", "call of duty", "Images", "ItemSearch", "1"));// now retrieve some data$totalPages = $xml->Items->TotalPages;echo "<p>There are $totalPages pages in the XML results.</p>";// retrieve data in a loopecho "<ul>\n";foreach($xml->Items->Item as $item){ echo "<li>".$item->ASIN."</li>\n";}echo "</ul>\n";?>\[/code\]