If you're looking to post data to a URL from PHP code itself (without using an html form) it can be done with curl. It will look like this:
$url = 'http://www.someurl.com';
$myvars = 'myvar1=' . $myvar1 . '&myvar2=' . $myvar2;
$ch = curl_init( $url );
curl_setopt( $ch, CURLOPT_POST, 1);
curl_setopt( $ch, CURLOPT_POSTFIELDS, $myvars);
curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt( $ch, CURLOPT_HEADER, 0);
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1);
$response = curl_exec( $ch );
This will send the post variables to the specified url, and what the page returns will be in $response.
Your question is not particularly clear, but in case you want to send POST data to a url without using a form, you can use either fsockopen or curl.
cURL-less you can use in php5
$url = 'URL';
$data = array('field1' => 'value', 'field2' => 'value');
$options = array(
'http' => array(
'header' => "Content-type: application/x-www-form-urlencoded\r\n",
'method' => 'POST',
'content' => http_build_query($data),
)
);
$context = stream_context_create($options);
$result = file_get_contents($url, false, $context);
var_dump($result);
Source: Stackoverflow.com