Well the http headers are in correct form only.. But can you please tell me why this error again?..and there is nothing wrong in syntax also...

go through the lists, check each and every single item until you find one that solves it

I wrote the code and tested it, I know it works,

Your most likely problem is either wrong copy/paste , wrong shebang, wrong lineendings, missing modules, ... use the list, I can't do it for you