PHP SendToHost function not working

PHP SendToHost function not working

So I'm currently trying to implement the 'SendToHost' function that is
widely used for 'GET' and 'POST' procedures. In my case, I want to use it
for sending a 'postcode' to a shopping website's postcode input form for
use with retrieving that postcode's specific catalogue. More specifically,
the code should automatically generate the web page that has the results
for the postcode. Below is my code coupled with the function and I'd like
to know why it isn't working:
function SendToHost($host, $method, $path, $data, $useragent=0)
{
// Supply a default method of GET if the one passed was empty
if (empty($method))
$method = 'GET';
$method = strtoupper($method);
$fp = fsockopen($host,80);
if ($method == 'GET')
$path .= '?' . $data;
fputs($fp, "$method $path HTTP/1.1\n");
fputs($fp, "Host: $host\n");
fputs($fp, "Content-type: application/x-www-form-urlencoded\n");
fputs($fp, "Content-length: " . strlen($data) . "\n");
if ($useragent)
fputs($fp, "User-Agent: MSIE\n");
fputs($fp, "Connection: close\n\n");
if ($method == 'POST')
fputs($fp, $data);
while (!feof($fp))
$buf .= fgets($fp,128);
fclose($fp);
return $buf;
}
echo
sendToHost('catalog.coles.com.au','get','/default.aspx','ctl00_Body_PostcodeTextBox=4122');