XML to CSV

I have an XML file that is in a cXML format. I need to convert this file to CSV. I would like to process the XML file to CSV using PHP. I have attached 2 files. The first is the sample XML file, the second is an example CSV file. I have mapped the fields in the CSV file that match the data needed in the XML file. I only want data in the CSV file, no tags. Please comment the PHP file because it will require modification. The php file should process the XML file on a loop because there may be multiple lines. "TBD" should remain as it will be filled in later. The overall structure of the CSV file must remain intact so the same amount of commas are in each H and D line as shown in the example. The amount of D lines depends on the amount of XML lines processed by the PHP script. Thanks for looking.