PHP curl implementation get and post code_PHP tutorial

$ch = curl_init("http://www.jb51.net/") ;
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true) ;
curl_setopt($ch, CURLOPT_BINARYTRANSFER, true) ;
$output = curl_exec($ch) ;
$fh = fopen("out.html", 'w') ;
fwrite($fh, $output) ;
fclose($fh) ;

//extract data from the post
extract($_POST) ;
//set POST variables
$url = 'http://www.jb51.net/get-post.php' ;
$fields = array(
'lname'=>urlencode($last_name) ,
'fname'=>urlencode($first_name) ,
'title'=>urlencode($title) ,
'company'=>urlencode($institution) ,
'age'=>urlencode($age) ,
'email'=>urlencode($email) ,
'phone'= >urlencode($phone)
);
//url-ify the data for the POST
foreach($fields as $key=>$value) { $fields_string .= $key.' ='.$value.'&' ; }
rtrim($fields_string ,'&') ;
//open connection
$ch = curl_init() ;
//set the url, number of POST vars, POST data
curl_setopt($ch, CURLOPT_URL,$url) ;
curl_setopt($ch, CURLOPT_POST,count($fields)) ;
curl_setopt($ch, CURLOPT_POSTFIELDS,$fields_string ) ;
//execute post
$result = curl_exec($ch) ;
//close connection
curl_close($ch) ;