thank you jason. i solved that error.
i couldnt see any spaces in dreamweaver or any errors. but when i went into my hosting server i edited the code from there and turns out my whole code started on line 2 and not from line 1. dont how that happened. but i fixed the bug thanks to you.
my other question now is. i have implemented the postage as you instructed.. but its not working.. i still get a flat rate of 8.50 for all transactions. and now my other problem is that the currency is in USD and there is no option to change to australian dollar (AUD). to attempt to fix this, in the checkout.php there was a line under currency i changed to AUD from USD. but still does not work. how can i fix this?