[galaxy-dev] Help with "Send output to Galaxy" function

Hi, I am trying to connect my local database/webpages to my local galaxy server. But I have a hard to implement "send output to galaxy" function. Right now I have a sending page to send a form to galaxy and it looks like everything goes well. From the variable json_params(data_source.py), I can see that all parameters have been received by galaxy. But the problem is that how I get my parameters from my getfile.php file(This is used in the Galaxy_URL too, the callback function)? I tried to print out $_POST, $_GET, $_REQUEST, nothing shows up. I did see some output from $_Server. I am using php. Please help! Best, Huayan