PHP and SSL

Alrighty, I have Curl installed and, apparently, working correctly. However, I still cannot seem to complete an online transaction. How does one go about encrypting the data to send? I've seem to have set up everything correctly. However, the code doesn't seem to do anything. I'll post code snippets here: ------BEGIN------ $ch = curl_init("https://secure.somesite.net/cgi/secure.dll"); $fp = fopen("response.txt" , "rw"); $data = "xval1=1234&yvale=4321"; curl_setopt ($ch, CURLOPT_FILE, $fp); curl_setopt ($ch, CURLOPT_HEADER, 0); curl_setopt ($ch, CURLOPT_POSTFIELDS, $data); curl_exec ($ch); curl_close ($ch); fclose ($fp); ------END------ Thanks, Jeremy