diff --git a/sample/ipn.php b/sample/ipn.php
index <HASH>..<HASH> 100644
--- a/sample/ipn.php
+++ b/sample/ipn.php
@@ -7,11 +7,11 @@ $isValidIPN = $yellow->verifyIPN(); //bool
 $log_file = "ipn.log";
 $payload = file_get_contents("php://");
 if($isValidIPN){
-    file_put_contents($log_file , $payload . "is valid IPN call " , FILE_APPEND);
+    file_put_contents($log_file , $payload . "is valid IPN call\n " , FILE_APPEND);
     /// you can update your order , log to db , send email etc
     header("HTTP/1.0 200 OK");
 }else{
-    file_put_contents($log_file , $payload . "is invalid IPN call " , FILE_APPEND);
+    file_put_contents($log_file , $payload . "is invalid IPN call\n " , FILE_APPEND);
     /// invalid/ fake IPN , no need to do anything
     header("HTTP/1.1 403 Unauthorized");
 }
\ No newline at end of file
update invoice class + create sample show case