Webpage, parse xml and download modified data

This is a hard one to explain so feel free to ask questions. General bids will generally be ignored especially if it shows you have not read the documentation. PHP would be the langage of choice but I'm open to suggestions on how to acheive the desired outcome. 1. Load the required xml file from a drop down list to display on webpage, ideally it would load look in directly and have a selection of these xml files to choose from. If easier then convert to json and use. 2. Only one xml file will be loaded at a time. 3. Load an *.abt file which will show against the xml data. 4. Once changes are made a new (in this case) [login to view URL] file will able to be downloaded. Multiple fields are required and the required output will look like the included .html. The layout may change so allow for this, css, tables etc. (Include html file is not interactive with change bits and is a guide only.) If I'm to select a different option for an item it should update the below hex text box data and vice versa, if I'm to change hex then the above selection boxes should update. LSB MSB bit location and byte size are important and all information is included in the xml. I have no need to see binary so it does need to be converted to hex as shown. checksum bits can be added as we progress as the xml does not contain this information but we can calculate later. Take into account [login to view URL] as larger files will definatly have more bytes per DE block 8 12 etc. The attached xml is a small file but no matter how many de blocks it should process the data in the same way. Never assume that DE00+ will be standard but the name is found in DID ID= anyway.