Best way to make xml file editable on web

[juancruz4]

I have a huge configuration file(xml based), which is frequently updated by the customer.Now i don't want user to make configuration changes directly to the file as user may enter invalid data which can invalidate the file.For now i have a form which takes inputs from user and then at server side i am using xpath to edit the xml.The UI experience is poor as you can enter multiple child tags to a parent and for each addition there's a postback to server and also it requires a lot of user inputs as to know where in the dom he wants to add the tags.Is there any way i can represent my xml in html editable form and provide user with dropdowns to select values from and also he can add new tags. I am open to technologies, JS, php, .net , java or any client side library.